Little is known about what factors predict the formation of reciprocal same-sex friendships during early adolescence. To examine whether social-emotional competencies aid in establishing and maintaining these friendships at the beginning and end of seventh grade, 380 German youth (mean age = 12.6 years; 49 percent boys; 100 percent White) reported on their peer support networks and on three broad categories of social-emotional competencies (i.e., non-constructive anger regulation, constructive anger regulation, emotional awareness, and expression disclosure). Regression analyses indicated the number of reciprocal friendships at Time 2 (T2) was predicted by adolescents' constructive anger regulation through redirection of attention, and social support when angry at the friend, even after controlling for Time 1 number of friends and peer acceptance. Among girls, willingness to self-disclose marginally predicted their number of reciprocal friends at T2. Results are discussed in terms of the specific social-emotional competencies that facilitate involvement in reciprocal friendships.