Recent interest in the selection of surgical trainees has been directed towards the use of aptitude tests. Using mainly senior surgeons' ratings of trainees' surgical ability for comparison, specific areas of objective investigation have included manual dexterity, spatial ability, personality, and decision-making ability. While certain spatial ability tests have been shown to correlate with ratings of surgical skill, tests of manual dexterity have not. Personality variables, specifically, show how surgeons deal with stress and decision-making ability, and are considered to be important within the profession. Although aptitude tests are being used in medical recruitment, there is still widespread disagreement over their inclusion and their validity. It is proposed that the use of aptitude testing in surgery is limited by three principal factors: there are too few well-designed studies investigating the basic psychological and psychomotor abilities considered to be specific to surgical skill; the use of subjective ratings of surgical ability as the independent variable in most studies; and the fact that, as yet, there is no working definition of superior surgical ability.