This study examined gender differences in self-silencing, the relationship between self-silencing and psychological distress, and reasons for self-silencing in informal cancer carers (329 women, 155 men), using a mixed-method design. Men reported greater self-silencing than women on the Silencing the Self Scale; however, women reported higher depression and anxiety, even though depression and anxiety were significantly correlated with self-silencing. These gender differences in patterns of self-silencing were explored in follow-up interviews with 34 women and 19 men carers, selected to represent a cross-section of cancer type and stage and analyzed using thematic decomposition and positioning theory. Both men and women reported self-silencing because of their desire to prioritize patient needs or to avoid conflict. However, women positioned self-silencing as a requisite for coping and demonstrated awareness of external judgment, reflecting self-policing linked to constructions of idealized femininity, in particular the positioning of women as natural carers. In contrast, men positioned self-silencing as a normal aspect of masculinity, regarding expressions of needs or feelings as signs of weakness and maintaining a positive front as a means of coping. These findings confirm that men and women self-silence for different reasons and with differential consequences for mental health. The significant association of self-silencing with depression and anxiety suggests that it is not an adaptive behavior for caregivers, supporting previous reports that avoidance of emotional discussion in couples living with cancer is detrimental to coping and to mental health.