Results indicated that Internet activity choices influenced later relationship quality in both best friendships and romantic relationships. Although instant messaging was positively associated with more aspects of romantic relationship and best friendship quality, visiting chat rooms and entertainment activities were either not related to or negatively related to best friendship quality and to romantic relationship quality. Using the Internet to play games and for general entertainment predicted decreases in relationship quality with best friends and romantic partners. The findings reflect the important function of online socializing for the development and maintenance of salient relationships in adolescence. The Internet appears to now be a significant aspect of the educational, social, and recreational experiences of adolescents. From a developmental perspective, future research is necessary to further learn about the impact of Internet activities on the social adjustment and relationship qualities of adolescents. Data were collected as part of a larger study to examine the influence of media consumption on adolescents' relationships. Schools in both rural and urban Canadian centers participated from March 2001 to May 2002. The sample consisted of 884 ethnically diverse students ranging in age from 14 to 18 years old. Tables, references