Background: Decreased respiratory muscle strength in patients with stroke may cause breathing difficulties, and cardiopulmonary function and exercise capacity may decline, which may reduce balance and gait ability. Objects: This study aimed to determine the influence of improved respiratory muscle strength on the recovery of balance and gait ability at discharge in patients with stroke. Methods: This prospective observational study involved 21 patients clinically diagnosed with stroke. Multiple regression models with a forward selection procedure were used to investigate whether the improvement of respiratory muscle strength (maximal inspiratory pressure [MIP] and maximal expiratory pressure) can contribute to the recovery of balance (Trunk Impairment Scale, Berg Balance Scale, Brunel Balance Assessment, and five times sit-to-stand) and gait (10-meter walk test, timed up and go, and 6-minute walk test [6MWT]) ability. Results: In the forward selection regression analysis, MIP was an influencing factor, accounting for 36.2% of the variance in the 6MWT. Conclusion: This result suggests that an improvement in MIP influences the increase in distance in the 6MWT. Therefore, it is important to evaluate respiratory muscle strength. Inspiratory muscle strengthening can recommended improving endurance and functional walking ability in patients with stroke.