Introduction: For conservative treatment of anterior cruciate ligament injury are suitable patients that have competent potential to compensate for the passive joint stability deficit by knee muscles. Purpose: The purpose is to find out to what extent we can improve muscle performance and decrease the joint instability with target programme of kinesiotherapy in patient with long-term anterior cruciate ligament and medial meniscus injury. Methods: Patient was involved in nine-week kinesiotherapeutic treatment. Measurement protocol consisted of subjective state evaluation with Lysholm and KOOS questionnaire, anthropometric measurements of muscle atrophy and range of motion, functional one leg hop test and Y balance test, measurement of maximum voluntary isometric contraction (MVIC) and isokinetic knee muscle testing at 60 and 180°/s of angular velocity. Results: After finished training the right thigh circumference increased by 1,1 cm in proximal part, 1,9 cm in distal part and calf circumference by 1,3 cm. The one leg hop test lengthened by 15,1 cm and posteromedial component of Y balance test improved by 17,2 cm. Torque at maximum voluntary isometric contraction of right leg flexors improved by 20% at both angle velocities, while isokinetic improved by 18% at 60°/s and 22% at 180°/s. Torque of extensor muscles did not significantly improved. Discussion and conclusion: Even though the hypertrophy of right thigh muscle has been achieved and the dynamic knee stability has improved, the patient has not achieved adequate stability in injured knee after training programme. Also, the deficit in torque of extensor muscles stays clinically significant. Based on results conclude that the patient cannot sufficiently compensate passive joint stability deficit only with conservative (non-operative) treatment.