The purpose of this study was to investigate the influence of the lateral wedge on asymmetrical weight bearing and posture in hemiplegic gait. The subjects were 2-female and 4-male moderate stroke patients, average age 54 +/- 6 yr. The time from onset was 127 +/- 69.7 days. A 7 mm-thick wedged insole was applied to the affected side for a week. Before and after that, the vertical ground reaction force, single supporting period and side movement of the trunk were recorded during walking. As a result, we found that the vertical ground reaction ratio and single supporting period ratio of the affected side (affected/unaffected) were significantly increased (P < 0.05), and also that the lateral sway of the trunk was remarkably decreased (P < 0.05). Our results indicate that the application of the lateral wedge for a week improved asymmetrical weight bearing and gait ability in moderate hemiplegic patients. Also we believe that a randomly sampled comparison study should be performed in the near future.