The primary objective of the present study was to investigate the peer interactions that facilitate or hinder adolescents’ negative emotion regulation. Using the Enhanced Critical Incident Technique, a 1-hour semi-structured interview was conducted with 16 junior high school adolescents. Participants were asked to recall emotionally salient situations during the past school year when they experienced strong negative emotions and indicate the peer interactions that helped, hindered, or could have potentially helped with regulating their emotions. Data analysis identified 182 critical incidents, represented by 109 helping incidents, 45 hindering incidents, and 28 wish list items, which were placed into the following 10 categories: (a) supportive presence, (b) expressing concern, (c) withdrawing, (d) empathizing, (e) encouraging and cheering up, (f) sharing perspective, (g) giving advice, (h) distracting, (i) taking action, and (j) punishing. Implications for mental health and service providers, parents, and adolescents, as well as recommendations for future research, are presented.