Objective: to characterize the role of comorbidity as a prognostic factor for clinical outcomes of nuclear magnetic resonance therapy and McKenzie physical rehabilitation techniques in degenerative shoulder joint diseases. Materials and methods. Treatment outcomes were analyzed in 21 cases of omarthrosis in 18 patients (11 (61.11%) men and 7 (38.89%) women; mean age — 58.28±11.59 years). The course of conservative treatment included 7 sessions of nuclear magnetic resonance therapy combined with McKenzie physical rehabilitation. Clinical outcomes were assessed using the Oxford Shoulder Score. Results. The mean outcome corresponded to excellent values (41.29±5.18 points). Excellent results were observed in 14 (66.67%) patients, good in 6 (28.57%), and satisfactory in 1 (4.76%). Factors associated with better outcomes included male sex (τ=+0.45, p=0.004), middle age (τ=+0.40, p=0.01), and lower Charlson comorbidity index (τ=+0.35, p=0.02). Poorer results were found in older patients (τ=−0.44, p=0.005), especially in the elderly (τ=−0.42, p=0.007), with heart failure (τ=−0.52, p=0.001), peripheral vascular disease (τ=−0.60, p=0.0002), and higher Charlson index (τ=−0.51, p=0.001). Men had higher odds of achieving excellent results (OR=9.17, CI (1.00–84.35), p=0.03). Peripheral vascular disease was associated with higher odds of good results (OR 13.00, 95% CI 1.17–144.90; p=0.02). Conclusion. Comorbidity has a significant impact on the clinical outcomes of comprehensive conservative treatment in patients with degenerative shoulder joint diseases.