Childhood physical and sexual abuse victims are at increased risk for developing depression, anxiety, and post-traumatic stress disorder (PTSD) in adulthood. Prior findings suggest abuse onset, duration, and severity moderate relationships between victimization and psychopathology. However, because these abuse characteristics are highly intercorrelated, their unique, individual effects on mental health outcomes remain unclear. To address this gap, the present study examined relationships between physical and sexual abuse characteristics and mental health outcomes and whether these relationships differed by sex. A diverse community sample of late adolescents and emerging adults (N = 1270; mean age = 19.68; 51% female) self-reported the onset, duration, and severity of physical and sexual abuse, as well as their depressive, anxiety, and PTSD symptoms. Results of a multivariate regression model (simultaneously evaluating all physical and sexual abuse characteristics) indicated that physical abuse onset in middle childhood and sexual abuse onset in middle childhood or adolescence were associated with all forms of psychopathology; and physical abuse onset at any time was uniquely linked with PTSD. Duration and severity of physical or sexual abuse did not predict psychopathology after accounting for time of onset. Multigroup analyses indicated that adolescence-onset and duration of sexual abuse respectively predicted anxiety and PTSD in females but not males, whereas sexual abuse severity predicted fewer PTSD symptoms in males but not females. Overall, results suggested that abuse occurring after age 5 may have the most deleterious impact on mental health.