In 1718 he was appointed an assistant surgeon at St Thomas' Hospital in London, becoming full surgeon in 1719 or 1720 where his specialisation of the removal of bladder stones resulted in the increase in survival rates. Afterwards, he was appointed surgeon for the stone at Westminster Infirmary and surgeon to Queen Caroline. He also improved eye surgery, developing new techniques, particularly in the removal of cataracts. Cheselden was selected as a surgeon at St George's Hospital upon its foundation in 1733.