BACKGROUND: The experience of child maltreatment (CM) is associated with a 2- to 3-fold increased risk of suicidal ideation and suicide attempts in adulthood. However, the underlying mechanisms are still largely unclear. This study investigated two prominent theoretical models on suicidal ideation and behavior to examine potential pathways: the Integrative Motivational-Volitional (IMV) model and the Interpersonal Theory of Suicide (IPTS). METHODS: 306 psychiatric inpatients (mean age = 36.9 years, 53.6 % female) admitted to psychiatric hospitals after an acute suicidal crisis (n = 145) or a recent suicide attempt (n = 161) were examined shortly after admission and three follow-up points over 12 months using validated measures of CM, suicidal ideation and behavior, defeat, entrapment, and capability for suicide with its subdimensions fearlessness about death (FAD) and pain tolerance (PT). Serial mediation and moderated moderation analyses were conducted to test the proposed pathways. RESULTS: Results showed positive associations between all CM subtypes and current suicidal ideation. The relationship between CM and suicidal ideation was indirectly mediated by defeat alone and in combination with entrapment, supporting the IMV model. Contrary to IPTS assumptions, CM did not increase capability for suicide, and there was almost no significant interaction between CM and the subdimensions of capability for suicide (FAD and PT) in moderating the transition from suicidal desire to intent to attempt. CONCLUSIONS: The study provides support for the IMV model while questioning certain IPTS assumptions regarding the relationship between CM and suicidal ideation and behavior in adulthood.