Introduction. Knee osteoarthrosis is a degenerative disease which induces intense trouble. Material and methods. The aim of the study was the parallel analysis of clinical and ultrasound examination in patients diagnosed with knee osteoarthrosis. A group of 88 patients underwent the clinical examination and the outflow and size of flexion were determined, the intensity of pain was assessed by the patient's mark on VAS, the functional ability by HAQ index, and the size of effusion and synovitis by arthrosonography. Results. The minimal outflow was diagnosed in 34.1% of patients, medium in 22.7%, and significant in 4.5%. Synovitis was evident in 67% of patients, 17.0% had nodular, 30.7% diffuse and 19.3% nodular-diffuse type. Effusion was observed in 75% of patients. The average size of synovitis in suprapatellar recess (SR) in the patients with significant, medium and lateral outflow was 6.68 (2.93-10.04) mm (p=0.000), 1.57 (0-5.53) mm (p=0.006) and 6.18 (3.44-7.10) mm (p=0.000), respectively. The grade of pain on VAS was the highest in patients with significant outflow 70(60-95) (p=0.014), effusion 60 (50-80) (p=0.024) and nodular type of synovitis 70 (50-90) (p=0.029). There was a significant correlation on VAS in the positive direction with the size of effusion (r=0.238, p=0.025) and synovitis in LR (r=0.215, p=0.044), HAQ index (r=0.502, p=0.000), and in the negative direction with the size of flexion (r=-0.346, p=0.001). The average size of flexion in the patients with significant outflow was 90 (82.5-90)°(p=0.000), HAQ index 1.99 (1.49-2.30) (p=0.078). HAQ index depended on effusion in LR in the positive direction (p=0.014). Discussion and Conclusion. Clinically significant outflow is shown by arthrosonography as the biggest in SR, moderate and minimal only in LR. Moderate or significant outflow, effusion and nodular type of synovitis lead to intensive pain. Patients with bigger functional disability had intense pain, significant outflow in LR and significantly limited motions.