OBJECTIVES To determine the relative effects of cobblestone mat walking, in comparison with regular walking, on physical function and blood pressure in older adults. DESIGN Randomized trial with allocation to cobblestone mat walking or conventional walking. SETTING General community in Eugene, Oregon. PARTICIPANTS One hundred eight physically inactive community-dwelling adults aged 60 to 92 (mean age+/-standard deviation=77.5+/-5.0) free of neurological and mobility-limiting orthopedic conditions. INTERVENTION Participants were randomized to a cobblestone mat walking condition (n=54) or regular walking comparison condition (n=54) and participated in 60-minute group exercise sessions three times per week for 16 consecutive weeks. MEASUREMENTS Primary endpoint measures were balance (functional reach, static standing), physical performance (chair stands, 50-foot walk, Up and Go), and blood pressure (systolic, diastolic). Secondary endpoint measures were Short Form-12 physical and mental health scores and perceptions of health-related benefits from exercise. RESULTS At the 16-week posttest, differences between the two exercise groups were found for balance measures (P=.01), chair stands (P<.001), 50-foot walk (P=.01), and blood pressure (P=.01) but not for the Up and Go test (P=.14). Although significant within-group changes were observed in both groups for the secondary outcome measures, there were no differences between intervention groups. CONCLUSION Cobblestone mat walking improved physical function and reduced blood pressure to a greater extent than conventional walking in older adults. Additional benefits of this walking program included improved health-related quality of life. This new physical activity may provide a therapeutic and health-enhancing exercise alternative for older adults.