Violent ideations are increasingly recognized as an important psychological predictor for aggressive and violent behavior. However, little is known about the processes that contribute to violent ideations. This paper examines the extent to which polyvictimization triggers violent ideations in late adolescence and early adulthood, while also adjusting for dispositional and situational factors as well as prior violent ideations. Data came from three waves of the Zurich Project on the Social Development from Childhood into Adulthood (z-proso; n = 1465). Full-information maximum likelihood Tobit models were fitted to regress violent ideations experienced at ages 17 and 20 on multiple victimization experiences in the preceding 12 months while controlling for antecedent developmental risk factors and prior violent ideations. The results showed that violent ideations in late adolescence and early adulthood are influenced by violent thoughts, aggressive behavior, violent media consumption, moral neutralization of violence, and internalizing symptoms measured 2 years earlier. Experiences of polyvictimization significantly contributed to an increase in violent ideations both during late adolescence and in early adulthood. The exposure-response relationship between victimization and violent ideations did not significantly differ by sex. The findings are consistent with the notion that violent ideations are triggered by a retaliation-linked psychological mechanism that entails playing out other directed imaginary aggressive scenarios specifically in response to experiencing intentional harm-doing by others.