Background. Injuries of meniscus are the frequent lesions in the knee joint (KJ). A big number of false-positive and false-negative outcomes may mislead not only a patient but also a specialist in traumatology and orthopedics. Functional and biomechanical studies of the knee joint might provide additional data for clinical decision making and diagnostics.Materials and Methods. The authors studied 47 patients with traumatic and degenerative tears of the KJ meniscus. All patients were divided into 3 groups. Group I included 10 patients analyzed before and after the arthroscopic treatment, Group II included 22 patients analyzed before treatment only and Group III included 15 patients analyzed after the surgical treatment only. The authors studied the gait biomechanics as well as hip and knee function. In Group I the time from disease onset to the surgical treatment was 9.7 months. The grade on the KOOS scale was 29.4 points before the treatment and 80.2 points after the treatment. In Group II, the grade was 34.2 points. In Group III, the grade was 85.6 point.Results. The temporal characteristics of the gait cycle did not exhibit any differences from the normal state in all the groups. In Group I a statistically significant increase of the hip extension amplitude was observed, both for the operated and the intact leg. In Groups II and III the authors did not observe this pattern. The abduction-adduction and rotation motions in the hip did not exhibit any significant changes in all the three groups. In Group I knee joint kinematics at the affected side did not differ from intact leg prior to the treatment. After the surgery the value of magnitude phase during the basic knee flexion at the operated side significantly decreased. The amplitude itself increased, but the difference did not reach a statistical significance due to high data dispersion. Patients of Group II and III also demonstrated significant difference in the phase of basic flexion with the same value on the intact side. The abduction-adduction motions were decreased at the intact side after the surgery in the first group.Conclusion. Thus, the meniscus injury results in slight disorder in the walking and biomechanics of the knee which are successfully compensated during one year after arthroscopic treatment.