Grima returned to Malta in 1763 and was immediately given the post of Chief Surgeon at the Holy Infirmary. Two years later he started lecturing on anatomy and surgery, and became holder of the Chair of Anatomy and Surgery. In 1771 he was nominated as lecturer in surgery and anatomy in two Italian colleges, yet he remained in Malta. Later on in 1781 Grima published a textbook, the Istituzioni d'Anatomia, to complement his lectures. Medical students from all over Europe travelled to Malta to learn under his tutorage. In 1783, GrandmasterEmmanuel de Rohan-Polduc commissioned him to test the legitimacy of the remedial measures of Mesmer'smethod of animal magnetism. Grima retired in 1797 and died on 25 August 1798. He is buried in the Church of the Minor Observants of St. Francis in Valletta.