Trait rumination is the tendency to overthink and focus on negative emotions and events and is related to a number of psychological disorders and maladaptive behaviors including nonsuicidal self-injury (NSSI). The purpose of this study was to conduct a meta-analysis of the relationship between trait rumination and NSSI behaviors. Results from 60 samples showed small effect sizes between trait rumination and NSSI engagement, NSSI frequency, and the number of methods used to self-injure in cross-sectional samples. Results from 13 samples showed small effect sizes between trait rumination and NSSI engagement and NSSI frequency in longitudinal samples. Moderator analyses indicated that this relationship is similar whether the type of rumination is depressive or not and is generally consistent across different ages, genders, and ethnicities. These results help clarify the role of trait rumination as a risk factor for NSSI.