Abstract Background The Interpersonal-Psychological Theory of Suicidal Behavior (IPT) is supported by recent epidemiological data. Unique risk factors for the IPT constructs have been identified in community epidemiological studies. Gender differences in these risk factors may contribute substantially to our understanding of suicidal risk, and require further investigation. The present study explores gender differences in the predictors and correlates of perceived burdensomeness, thwarted belongingness and acquired capability for suicide. Methods Participants (547 males, 739 females) aged 32–38 from the PATH through Life study, an Australian population-based longitudinal cohort study (n=1,177) were assessed on perceived burdensomeness, thwarted belongingness and acquired capability for suicide using the Interpersonal Needs Questionnaire and Acquired Capability for Suicide Survey, and on a range of demographic, social support, psychological, mental health and physical health measures. Gender differences in the predictors of the IPT constructs were assessed using linear regression analyses. Results Higher perceived burdensomeness increased suicide ideation in both genders, while higher thwarted belongingness increased suicide ideation only in females. In females, thwarted belongingness was uniquely related to perceived burdensomeness, while greater physical health was significantly associated with greater thwarted belongingness in males but not in females. There were trends suggesting greater effects of being single and greater perceived burdensomeness for men, and stronger effects of less positive friendship support for women associated with greater thwarted belongingness. Conclusions Men and women differ in the pattern of psychological characteristics that predict suicide ideation, and in the factors predicting vulnerability. Suicide prevention strategies need to take account of gender differences.