He was educated for the medical profession, and in October 1804 was appointed assistant-surgeon in the 3rd dragoon guards, with which regiment he served in Portugal under Lord Beresford.
In August 1812 he was promoted to the rank of surgeon on the Portuguese staff, but at the close of the Peninsular war he returned to Edinburgh, and resumed the study of drawing in the Trustees' school.
In 1816 and 1817 he exhibited at the Society of Painters in Watercolours four views in Spain and Portugal, and in 1821 he sent to the Royal Academy an oil-painting, ‘Recollection of the Serra da Estrella, Portugal.’ He afterwards held an appointment in the General Hospital at Fort Pitt, Chatham, and while there he made many drawings for the Museum of Morbid Anatomy.
In August 1823 he was promoted to be deputy inspector of hospitals on the West Coast of Africa, and accepted the post in the hope of being able during his five years' service to explore the region visited by Mungo Park.
Two pictures representing actions of the Brune frigate, painted by him in conjunction with his brother John Christian Schetky, were exhibited at the Royal Academy in 1825.