On 20th June, 1839 Pearce set sail from Plymouth on board the 'Plantagenet', Captain Domett, accompanied by four new Missionaries, Messrs. Tucker, Phillips, and Morgan, with their wives, and Mr. Wenger, together with religious friends Miss Wright and Mr. G. Beeby. The voyage was monotonous as almost all voyages to India were. He spent his time teaching Bengali, and learning Hindustani or Urdu. The passage was speedy as it only lasted 90 days. They arrived at the mouth of the Hooghly on 24th September, 1839, and landed on the 27th. Two passengers died during the voyage.

It seemed possible that he had ten or fifteen useful years before him 'after being so long accustomed to and Indian climate' as he was only 46. 'But before ten months, yea before ten weeks were past, all their hopes were blasted.' 'He had been gradually withdrawing from all other engagements that he might be employed more fully in the work of God.'

'The two last works on which his heart was set, and which he hoped to see completed, were the Bengali Bible with headings to the chapters, and references and literal renderings at the foot of the page; and a reprint of Martyn's version of the New Testament in Persian, but instead of living to see them finished, he did not live to see the first form of them through the press. The Bengali had been kept waiting for him for three years, while he was seeking in his native isle renovated health to engage in it: and when he had returned with health in some degree restored and fitted for work, he was removed before the first sheet could be struck off.'

On Saturday 14th March, 1840, William Pearce and William Yates spent the evening drinking tea, reading the Scriptures and praying. It was their usual practice to spend Saturday evening at each other's houses. Nothing particular occurred and before they parted they set out a plan for printing the Scriptures. On Sunday Pearce preached at the native Chapel as usual. In the evening he intended to have with him the native preachers and catechists for instruction, but something prevented them from attending. So being at liberty he attended the 'English place of worship.' 'So far from supposing this would be the last time he would be seen there, all his friends who had an opportunity of speaking with him, congratulated him upon his improved appearance in health and strength; for he was now recovered from the bilious attack which he had lately experienced.

On Monday 16th he wrote to the Society in England, drew up an appeal to the American and Foreign Bible Society, and conversed with members of his Church. In the appeal he wrote: 'How long we may all be spared together, or how soon disease and death may remove the most efficient labourers from the scene of action, is to us quite unknown; but we feel these circumstances to be a solemn call to us, to work while it is called to-day, and to do with all our might, whatever work God in his providence may seem to put in our hands.'

The same day he contracted cholera. His strength rapidly diminished. Lying in bed with his friends and a doctor by his side, a friend 'came in, and after quoting some consolatory passages of Scripture, to which he responded by occasionally raising his hand, asked him how he felt. He replied, I hope in Christ, I hope in Christ,' His friend quoted 'Unto you that believe, he is precious.' He answered 'I know him to be so, -- infinitely.' Perceiving that all would soon be over, his friend said, 'You are going to your Lord and Master.' He instantly replied, 'A most unworthy servant.' These were nearly the last words he spoke audibly... ...Soon after this, Mr. Pearce seemed gradually to sink into insensibility, and about 9 o'clock (the next morning) the scene was closed.'

'Thus within twenty-four hours was one of the most active animated bodies changed into a lifeless corpse.'

'The funeral was attended by a vast concourse of ministerial and other friends -- we may add, we believe by every convalescent Missionary in the city. The deep feeling manifested by all parties, showed how evidently he was sorrowed for in death. Previously to his removal from the Mission premises, suitable portions of scripture were read by the Rev. J. D. Ellis, and an affecting prayer was offered by the Rev. W. Yates. Mr. Yates is, by this mournful event, left the last of those who originally formed the Calcutta Mission. At the grave's mouth a striking and affecting address was delivered, and a prayer offered by the Rev. F. Tucker. The pall was borne by the following Missionaries: the Rev. W. S. Mackay, of the Scottish Mission; the Rev. F. Wybrow, of the Church Mission; the Rev. Messrs. Gogerly, Lacroix, and Boaz, of the London Mission, and others.

His foster-father, Rev. Nichols, had left him £1,000 in 1835. William left this in his will to Bristol, Stepney, and Horton Baptist Colleges, and to the propagation of the Gospel in Ireland. His biographer and successor as Superintendent at Baptist Mission Press, Dr. Yates, married William Pearce's widow Martha.

An obituary for William Pearce appeared in the 'Friend of India', published by John Clark Marshman. In it Marshman describes Pearce as being 'trained to the art of printing in one of its best schools, under Mr. Collingwood, Printer to the University of Oxford.'. He set up Baptist Mission Press 'which rapidly acquired a just celebrity, by the elegance and the punctuality of its work.'

He goes on to say: 'Speaking then of our deceased brother in the language of historic truth and sincerity, we would say that of all the Missionaries sent out by the Society he appeared to us to approach the nearest to the three illustrious men who planted Christian Missions in these regions, in his power of creating, combining and sustaining a system, the influence of which should affect the future destiny of society; though; in our humble judgment, he wanted their comprehensiveness of views.

In the management of business he was punctual and indefatigable. Nothing lagged in his hands. His time was not, like that of too many men, perpetually incumbered with arrears of business, but by an admirable system of economy, was always free for the prosecution of future arrangements.'

His attachment to the Baptist Missionary Society became, indeed, one of the most powerful principles of action, by which his life was governed; and to the promotion of its interests he devoted himself with a zeal and earnestness for which the Society will, with difficulty, find a substitute.'

His loss would at any time have been severely felt by his friends and by the cause of Christian benevolence; but at the present moment, when the Baptist Mission in India has been more than doubled by the junction of the Serampore Mission, and the arrival of many additional labourers in India the loss of one possessed of such qualifications and experience, must be peculiarly felt.'

An obituary appeared in the 'Literary Gazette' written by the Principal of the Hindu College.

'Calcutta Society has lost during the past week one of its most valuable members. We allude to the late Rev. W. H. Pearce. He was chiefly known to the literary world as for many years the active and judicious superintendent of the Baptist Mission Press, the largest and best establishment of the kind in this country. It was the first Printing Office in India that sent out works which in respect of paper and typography was equal to the Publications of the London Press. As a business man he was singularly attentive and obliging, indefatigably industrious, and of unimpeached integrity. His word was always as good as a written agreement. But admirable as was his character as a man of business, his loss will be far more deeply felt as a Christian Missionary and private Gentleman.'