BACKGROUND: Slips are a common cause of falls, and nonslip socks have been marketed to prevent slips in older people. However, few studies have investigated the biomechanical and clinical effects of walking in nonslip socks. This study aimed to examine gait parameters in older people walking on a slippery surface wearing nonslip socks compared with standard sock and barefoot conditions. METHODS: Fifteen older people completed five trials of the fast-paced Timed Up and Go test while barefoot and while wearing standard socks and nonslip socks. Kinematic data (step length, heel horizontal velocity at heel strike, and foot-floor angle at heel strike) and clinical data (total Timed Up and Go test time, total number of steps, number of steps in turn, and observed slips, trips, or falls) were collected. RESULTS: Performance on the Timed Up and Go test did not differ between the barefoot and nonslip sock conditions; however, participants walked more slowly and took shorter steps when wearing standard socks. Participants rated nonslip socks to feel less slippery than barefoot and standard socks. CONCLUSIONS: Compared with wearing standard socks, wearing nonslip socks improves gait performance and may be beneficial in reducing the risk of slipping in older people.