PURPOSE: The purpose of this study was to investigate the effects of calf tightness on gait, plantar pressure, and balance in adults. METHODS: A total of 60 participants were divided into a normal group of 30 subjects with normal dorsiflexion angle (20-25 degrees) and an experimental group of 30 subjects with limited dorsiflexion angle (0-15 degrees) due to calf tightness. Gait ability and foot pressure of the subjects was measured with a treadmill, and the balance ability was measured by PROKIN system. RESULTS: A significant difference in COP length, loading response, and single limb support was observed between groups. The COP length and single limb support ratio in the normal group was greater than in the experimental group, but the experimental group showed a higher ratio for loading response in the gait ratio. CONCLUSION Our results indicated that calf tightness was negative effects on balance and gait ability, so assessment of the muscle tightness should be considered during exercise and treatment.