This questionnaire study used a model of mental health proposed by Warr (1987, 1993) to examine how 8 aspects of the work situation (principal environmental influences, PEIs) were associated with psychological well-being, measured on several dimensions. It is hypothesized that the importance of different PEIs for well-being will be influenced by gender, particularly the relationship between control and work-related mental health. The results of multiple regression analysis indicated similarities and differences in the association of PEIs with well-being in males and females. In the male sample, control at work was significantly associated with all dimensions of work-related mental health; but in the female sample, it was not associated with any dimension of mental health. The influence of gender is discussed.