Objective: To examine the role of physical activity (PA) companions in supporting PA participation among African American women. Methods: Data were collected through in-depth interviews and focus groups. Fifteen physically active African American women participated in the study. Grounded theory data analysis techniques were used to develop a taxonomy depicting roles of PA companions for African American women. Results: PA companions functioned in 4 different roles: motivational, social, facilitative, and instructional. Supportive behaviors associated with each role were also elucidated. Conclusions: These findings provide an understanding for the function of companions in sustaining active lifestyle that can be used to inform intervention development.