In this study the relationship between degree of spasticity and strength of knee extensor and ankle plantar flexor muscles of post stroke hemiparetic patients has been investigated. Materials methods: The participants of this study were 40 stroke patients whose elapsed time of stroke onset was at least 3 months. Their age averaged 59 years. Spasticity was measured with the Modified Ashworth Scale. Isokinetic muscle strength was measured with an isokinetic dynamometer.