The aim of this study was to evaluate effects of hydrotherapy on postural control and electromyography parameters in men with chronic non-specific low back pain. Thirty men with chronic non-specific LBP divided into two hydrotherapy and control groups, randomly and equally. Electromyographic activity of erector spinae muscles and balance measured for both of groups before and after intervention. Hydrotherapy program was consisted of 24 sessions. Subjects in control group didn’t have any special activity. Two-way variance was used to interpret the data and correlated and independent T-tests were used for analysis of data at the significance level of (P<0.05). Electromyographic activity of lumbar erector spinae muscles in both of sides didn’t indicate a significant difference before and after intervention (P>0.05). However, a significant difference observed between two groups in balance index (P<0.05).