Whood practised for many years as a portrait-painter in Lincoln's Inn Fields, London. His portraits of ladies were considered some of the best of the time. He was especially patronised by John Russell 4th Duke of Bedford, for whom he painted numerous portraits of members of the Spencer and Russell families, destined for Woburn Abbey; some of these were copied by Whood from other painters. At Winchester College there are portraits of twelve gentleman commoners from 1731. At Cambridge there are portraits by Whood at Trinity College, including one of Isaac Barrow, and a Trinity Hall. There is a portrait of Archbishop William Wake by Whood at Lambeth Palace painted in 1736.

Some of his portraits were engraved in mezzotint, notably one of Laurent Delvaux the sculptor, engraved by Alexander Wan Haecken. Whood's drawings include some in chalk and black lead. In 1743 he executed a series of designs to illustrate Samuel Butler's Hudibras. The portrait of Joseph Spencer prefixed to his Anecdotes was engraved from a portrait by Whood.

His best work has been compared to that of Sir Godfrey Kneller, the foremost artist of his time.