Positive mental health (PMH) has been shown to confer resilience against suicide ideation. However, the mechanisms underlying the positive effect of PMH on suicide ideation/behavior are largely unknown. The current study aimed to determine whether positive affect mediates the association between PMH and suicide ideation.A total of 150 adult outpatients (65.3%; female; age: M(SD)=37.79(13.50), range:18-77) completed measures on PMH, positive and negative affect, as well as suicide ideation. Data were collected using self-report questionnaires. Linear hierarchical regression analysis was used to analyze the data. Positive affect was considered to mediate the association between positive mental health and suicide ideation.While positive affect fully mediated the significant negative association between PMH and suicide ideation, negative affect did not reveal to be a significant mediator of this relationship.The protective influence of PMH against suicide ideation is due to heightened positive affect: If positive mental health translates into positive affect, then suicide ideation becomes less likely.