Language is drawn on extensively in friendships but has received scant attention in the developmental literature. This study compared friendship quality in 16-year-old adolescents with and without specific language impairment (SLI), testing the extent it is predicted by individual differences in social behaviors and language ability. Participants were 120 adolescents with SLI and 118 typically developing (TD) adolescents. After considering the effects of nonverbal IQ and prosocial and difficult behavior, language measures were found to be associated with friendship quality. The TD participants enjoyed normal friendships, whereas the participants with SLI were more likely to exhibit poorer quality (although 60% experienced good quality of friendships). Longitudinal analyses identified early language difficulties as predictive of poorer friendship quality in adolescence.