Introduction Osteoarthritis (OA) is one of the most common causes of musculoskeletal system’s ailments. In the prevention of the disease and in its comprehensive treatment, proper health-related behavior becomes an extremely important factor for maintaining an optimal health condition. The aim of the study is to assess the relationship between the reported pain and the disability level, and the health-related behaviors undertaken by OA patients as well as their acceptance of the disease. Materials/Methods The study group consisted of 198 patients with diagnosed OA, according to ACR criteria (1988). The method used in the study employed a Pain VAS (0-10), Health Assessment Questionnaire Disability Index (HAQ DI 0-3), Acceptance of Illness Scale (AIS 8-40) and Health and Behavior Inventory (IZZ 24-120). Results The average age among respondents with OA has been 59.16 years of age (±15.87), duration of disease 5.5 years (±4.32). Pain experienced both during movement (rs = 0.319, p < 0.001) and at rest (rs = 0.382, p < 0.001) correlated positively with physical disability (HAQ DI). Studies indicated a positive linear correlation between the age and physical disability (rs = 0.200, p = 0.005). Acceptance of the disease (AIS) depends mostly on age (rs =  − 0.325, p < 0.001), on pain in motion (rp =  − 0.209, p < 0.001) and at rest (rp =  − 0.218, p < 0.001) and on the disability levels (rp =  − 0.353, p < 0.001). Analysis of the health-related behaviors (IZZ) indicates that the average severity of declared behavior is statistically significant with physical disability (HAQ DI) (p = 0.029). Conclusions The acceptance of illness is significantly reduced with age and progressive levels of disability as well as with the severity of pain. The progressive levels of disability and the younger age of the respondents motivate them to engage in health beneficial behavior.