Both degenerative and inflammatory arthritis cause disability that has deteriorative effect on patients' daily activities. The aim of this study was to determine the disability level of patients with chronic degenerative and inflammatory arthritis and evaluate the relationship of different activities with disability. Sixty-three rheumatoid arthritis (RA) and 39 osteoarthritis (OA) patients who were hospitalized in our clinics to receive physical therapy and rehabilitation were included in this study. The patients were evaluated for severity of pain (Likert), functional stage (Steinbrocker), and physical disability (Stanford Health Assessment Questionnaire). The severity of pain was higher and functional stage was more advanced in the RA group (P<0.05). Disability levels were mild in 38%, moderate in 44.5%, and severe in 16% of RA patients. In contrast, disability levels of OA patients were mild in 84.5% and moderate in 13%. The total disability score and the disability scores of activities, such as dressing, eating, hygiene, reaching for an object, and gripping an object were significantly higher in the RA group than in the OA group (P<0.05). Disability in walking and rising were not different between the two groups (P>0.05). Although the parameters that strongly correlated with general disability were gripping, hygiene/grooming, running errands, and shopping in the RA group, they were walking, running errands, and shopping in the OA group. Degenerative arthritis can cause as much disability as inflammatory arthritis regarding activities related with lower extremity functions. Thus, while planning treatment these factors must be determined and an appropriate multidisciplinary rehabilitation process should be initiated.