Matched groups of problem and social gamblers were compared in terms of their locus of control and their responses to the Myers Briggs Type Indicator. Contrary to previous studies no significant differences occurred on the locus of control measure. It was hypothesized that problem gamblers would be more extraverted and intuitive than social gamblers. However, none of the four scales on the Myers Briggs Type Indicator showed a significant difference between the groups. These findings and the results of earlier studies are compared and discussed. Earlier studies are difficult to interpret because of inappropriate or inconsistent controls. It is suggested that future personality studies of problem gamblers differentiate between different types of gambling and different types of problem gamblers.