Objective To evaluate muscle strength, balance control and gait capacity in patients with multiple sclerosis (MS) and to study the correlations between these parameters. Patients and methods Twenty MS patients were evaluated in terms of knee muscle strength, gait and balance parameters. These evaluations were performed using an isokinetic dynamometer (the Cybex II ®), a Bessou gait analyzer and a Satel ® force platform, respectively. The patients’ results were compared with those of a healthy control group. Results Hamstring and quadriceps peak torque values were lower in the MS group than in the control group. The sway area was greater in the MS group under eyes-open and eyes-closed conditions. The MS patients displayed lower gait speed, cadence and stride length. Hamstring and quadriceps strength values were significantly correlated with posture and gait parameters. Conclusion The present study revealed the value of an overall evaluation of knee muscle strength, gait and posture in MS patients.