UNLABELLED: This study examined the determinants of attaining/not attaining 10 000 steps per day among older women. METHODS: Daily step counts over 7 days were measured using accelerometry. Self-reported environmental characteristics, self-efficacy, social support and functional limitations were assessed in 128 older women. The presence of areas for activity within 1 km of each participant's residence was assessed using Geographic Information Systems. Multivariate analysis of variances were used to examine the degree to which these groups differed on measured constructs, and discriminant analysis was used to determine the profiles that discriminate among those who did not attain 10 000 steps per day and those who did. RESULTS: Participants who did not attain 10 000 steps per day reported lower self-efficacy (P < 0.05), greater functional limitations (P < 0.05), had significantly fewer walking paths (P < 0.05) within 1 km of their home and reported significantly less street connectivity (P < 0.05) and safety from traffic (P < 0.05) than those who achieved 10 000 steps per day. CONCLUSION: Lack of perceived and actual environmental supports for walking, more functional limitations and lower self-efficacy are barriers to achieving 10 000 steps per day. The absence of these individual and environmental characteristics inhibits walking behavior in older women and should be considered in campaigns to promote a physically active lifestyle.