Introduction Sexual harassment is associated with several mental health problems, including suicidality. Despite its terrible consequences for individuals, it is frequently an invisible occupational risk. Women are more likely to be harassed than men. However, little is known about gender differences and effect modification on this association.

Objectives To analyse the association between sexual harassment at work and suicidal ideation(SI) in civil servants from a state in Southern Brazil, investigating gender differences and interaction.

Methods This is a cross-sectional study with data from a web survey with employees from the Federal Judicial Court in Southern Brazil. Sexual harassment was evaluated using a structured questionnaire with specific questions about harassment and violence. SI was assessed using the Self-Reporting Questionnaire (SRQ-20). Poisson regression was used to test associations of interest and estimate prevalence ratios (PR). Stratified analyses by sex were performed.

Results 1,636 workers provided complete information. The prevalence of self-reported sexual harassment was 5.6%, 2.7% among males and 8.2% among females. The prevalence of SI was 4.2%, 5.0% in males and 3.5% in females. Among harassed men, the prevalence of SI was 27.3%. Sexual harassment was positively associated with SI after adjustment for age and educational level(PR 2.31; 95%CI 1.13–4.72). In the analysis stratified by sex, the association remained positive only in males (PR=4.70; 95%CI 1.90–11.66), after adjustment for age, educational level and personality traits.

Conclusions Gender play an important role in the association between sexual harassment and suicide. Approaching the understanding of gender to the measured variable of sex, the social role of masculinity may explain the high effect magnitude in men. Given that women are more frequent targets of sexual harassment, a sexist social and organisational context may mask the effect of this unacceptable violence in women. Also, there might be a possible normalization of the practice with necessary adaptation of women.