Purpose: The aim of this study was to investigate the effects of interferential current therapy (ICT) on spasticity, ROM, and the balance function in patients with stroke. Methods: 30 inpatients with stroke were randomly divided into 2 groups: the ICT group (n=15) and the placebo-ICT group (n=15). Two groups have got the traditional rehabilitation for 30 minutes before applying either ICT or placebo-ICT stimulation. The stimulus of ICT has been applied to gastrocnemius at the level of 100 Hz, two times of sensation threshold, while the placebo-ICT group has put on the electrode without electrical stimulus. To assess spasticity in ankle, the modified Ashworth scale (MAS) was used, and goniometer was applied to measure the passive range of motion (PROM). Also, the Berg Balance Scale (BBS), the Timed-up and go (TUG), and the Functional Reach Test (FRT) were carried out to examine the balance ability. Results: The ICT group showed a significant reduction of spasticity and significantly increased PROM than the placebo-ICT group (p<0.05). The placebo-ICT group did not show significant changes in the BBS, the TUG, and the FRT, while the ICT group significantly improved the BBS, the TUG, and the FRT (p<0.05). Conclusion: Our results demonstrated that ICT applied to gastrocnemius effectively decreased spasticity and improved range of motion and balance function in patients with stroke.