Background <p>Atypical reward responsiveness is crucial for the onset and maintenance of non-suicidal self-injury (NSSI). There is no consensus whether NSSI is associated with increased or decreased reward responsiveness, due to different reward modalities, stages of reward processing examined, and the confounding effects of psychiatric comorbidities. This study aims to investigate reward responsiveness across different reward modalities—monetary and emotional—as well as distinct phases of reward processing, namely anticipatory and consummatory stages, among adolescents with NSSI.</p> Methods <p>The monetary and affective incentive delay (MID &amp; AID) tasks were utilized to compare anticipatory and consummatory emotions as indicated by self-reported valence ratings between adolescents with NSSI (<i>n</i> = 103) and controls (<i>n</i> = 94) via ANOVA. The NSSI group was further separated into the NSSI + Suicidal Attempt (SA) and NSSI-only subgroups to examine whether NSSI co-occurring with suicidal behaviors resulted in more severe reward abnormalities. Sensitivity analyses using ANCOVA and hierarchical regression controlled for anhedonia symptoms to test the specificity of associations with NSSI.</p> Results <p>Adolescents with NSSI reported lower positive emotions when anticipating rewards, and experienced less pleasure after winning rewards or avoiding punishment. The NSSI + SA subgroup, compared with NSSI-only adolescents, had less consummatory pleasure in the MID task. However, blunted reward responsiveness in NSSI was no longer significant after controlling for anhedonia symptoms.</p> Conclusions <p>NSSI is correlated with blunted reward responsiveness, primarily confounded by depressive symptoms (especially anhedonia). Co-occurring NSSI and SA is a more severe form of self-harm.</p>