From a sample of psychiatric referrals who had completed the MMPI the following three groups, matched for age and sex, were derived: 42 patients with a history of a serious suicide attempt, 42 patients with a history of a non-serious attempt, and 126 patients who had neither attempted nor contemplated suicide. Non-serious suicide attempters were shown to be the most deviant group and differed to a significant extent from each of the other two groups on the Dependency, Hostility and Unconventionality scales. Male non-serious attempters showed the most disturbed personality profile. This implies that there is, for males, a higher personality threshold for making a non-serious attempt, which may account for the fact that suicide attempts, most of which are non-serious, are commoner among females.