Negative urgency, the self-reported tendency to act impulsively when distressed, increases risk for nonsuicidal self-injury (NSSI). NSSI is also associated with impaired negative emotional response inhibition (NERI), specifically negative emotional action termination (NEAT), a cognitive process theoretically related to negative urgency. We previously found that adults with NSSI history had difficulty inhibiting behavioral responses to affective images depicting negative content (but not positive or neutral images) in an Emotional Stop-Signal Task. We sought to replicate this finding, determine whether this deficit extends to negative emotional action suppression (NEAS; an earlier stage of NERI), and explore whether impairment in these two stages of emotional response inhibition helps explain the relationship between negative urgency and NSSI. 88 adults with NSSI history (n = 45) and healthy control participants (n = 43) without NSSI history or psychopathology completed a clinical interview, symptom inventories, an impulsivity questionnaire, and behavioral assays of early and late NERI (NEAS and NEAT, respectively). The NSSI group had worse NEAT than the control group in the Emotional Stop-Signal Task, but no group differences in NEAS were observed in an Emotional Go/No-go task. However, both early and late stages of NERI accounted for independent variance in negative urgency. We additionally found that NEAT explained variance in the association between negative urgency and NSSI. These results suggest that impulsive behavior in NSSI may involve specifically impaired inhibitory control over initiated negative emotional impulses. This deficit in late response inhibition to negative emotional stimuli might reflect a cognitive mechanism or pathway to elevated negative urgency among people who self-injure.