This study compared two interventions in terms of impact on physical activity participation and mother-daughter relations. Previously sedentary mothers and daughters (N = 34) were randomly assigned to a 12-week university-or home-based physical activity group. Program activities were designed using focus group information, aspects of the social cognitive theory, and information from previously successful interventions. The university-based group met three times a week for fitness building and recreational activities. The home-based group received a packet of information and training to perform activities in or near the home. Changes in physical activity and family bonding were assessed for mothers and daughters separately using a 2 (group)(2 (time) repeated measures analysis of variance. On completing the program, mothers and daughters in each group reported increased participation in physical activity (p = 0.02 to 0.000). The majority of mothers (94%) and daughters (88%) agreed that "my relationship with my daughter/mother has improved as a result of participating in physical activity together." On the Parental Bonding Instrument daughters reported no statistically significant changes in their perceptions of "mom's level of caring" (p = 0.73); however, "mom's level of control" (p less than or equal to 0.05) increased. Group by Time interactions were not significant, indicating that there were no differences between results from either program. Both home- and university-based physical activity programs may be viable paradigms in which to improve family relations and increase physical activity. (Contains 6 tables.)