Non-suicidal self-injury (NSSI) is an alarming public health concern that is particularly widespread among adolescents. The current study examined affective responses during mother-daughter interactions in adolescent girls with and without a history of NSSI. Participants were 60 girls aged 13–17 with (n = 27) and without (n = 33) a history of NSSI and their mothers. Adolescents and their mothers completed two interaction tasks: one positive and one negative. During these interactions, facial affect was assessed via electromyography (EMG). Results of Actor-Partner Interdependence Modeling (APIM) revealed several intra- and interpersonal disruptions in affect during both tasks among dyads in which the adolescent had an NSSI history. Findings suggest deficits in both self- and co-regulation of facial affect during mother-daughter interactions involving dyads in which the adolescents reports NSSI. Ultimately, if replicated and extended in longitudinal research, these disruptions may prove to be promising targets of intervention to reduce risk for future NSSI in adolescent girls.