Social support is an important construct in people's lives and in group counseling. The purpose of this study was to explore the associations among the individual's attachment style, group process variables (climate and bonding), and objectively documented supportive behavior in counseling groups, as well as their impact on change in members' perceived social support. Participants were 178 university students in 14 counseling groups of a supportive-expressive type. Support behavior was analyzed by the Social Support Behavior Code (Suhr, 1990) based on transcripts of all sessions. In addition, participants completed questionnaires pertaining to attachment style, group climate, bonding, and perceived social support. Results found attachment to be the strongest predictor of the observed provision and receipt of social support. It was also associated with group climate variables and with perceived social support. Negative behavior was also associated with group climate variables. However, observed group support was not associated with perceived social support, and no change was found in perceived support following treatment.