Objectives: Non-suicidal self-injury (NSSI) has been theoretically, clinically, and empirically associated with emotional dysregulation. NSSI is a means of regulating emotional states, particularly negative emotions. However, empirical studies on this topic are scarce and the literature lacks qualitative research on individuals' perceptions and comprehension of the function of self-injury. Thus, this qualitative study aimed to provide novel insights into the relationship between NSSI and emotional dysregulation in young adults. Methods: Twelve participants (mean age=22.7 years, 9 females and 3 males) from different support groups and a healthcare center participated in semi-structured interviews on NSSI-related emotional processes. Three aspects were investigated: reasons for NSSI, function of NSSI, and emotions. Each interview was voice recorded and typically lasted between 20 and 40 minutes. All responses were analyzed using thematic analysis. Results: Four major themes were identified. The results showed that NSSI had both intrapersonal and interpersonal functions, within which emotional regulation played a significant role. NSSI was also used to regulate positive emotions. The results also showed a sequence of emotions among the participants, going from feeling overwhelmed to feeling relatively calm but guilty. Conclusion: NSSI has several functions for the same individual. Thus, it would be interesting to provide integrative therapy, such as emotion-focused therapy, which focus on improving intrapersonal and interpersonal emotion regulation skills and strategies.