The purpose of this study is to qualitatively identify environmental characteristics that act as barriers and facilitators of physical activity among urban African-American adolescents—a population with disproportionately low levels of physical activity. The study used concept mapping, a participatory research methodology, with 50 adolescents in Baltimore, Maryland to identify the strongest environmental barriers and facilitators. Young women identified social environmental factors (e.g., crime, violence, drugs) as their strongest barriers to physical activity. For young men, other barriers (e.g., transportation, finances, and parental influences) were equally as strong as social environmental factors. Social support and neighborhood locations for physical activity were identified as facilitators of physical activity, with social support being the strongest facilitator for male and female participants. This study identifies age and culturally relevant environmental characteristics that should be examined in quantitative studies and considered in future interventions addressing physical activity in a high-risk population.