This study was a retrospective analysis of injuries sustained by women (mean age 60.9) who completed a 24-week walking intervention. We hypothesized that those who walked 60 min, 5 days/week (n = 27) were more likely to have an injury than those who walked 3 days/week (n = 27), and that predisposing conditions would lead to more injuries. We also examined the effect of the initial 4 weeks’ walking progression on likelihood of injury. A total of 12% of the walkers reported injuries necessitating program withdrawal, 18% reported minor injuries, and 26% reported injuries requiring medical treatment. Age, weight, cardiovascular fitness level, and walking volume were not significantly related to injuries. Women with prior musculoskeletal conditions were more likely to sustain injuries requiring medical treatment (p < .01). For these women, the initial progression may have been too rapid, suggesting that musculoskeletal screening and gradual progression guided by staff is important for moderate as well as intense activity programs.