This study was performed to investigate the relationship between bone mineral density (BMD) and disease activity in patients with rheumatoid arthritis (RA) treated with low dose prednisolone. Thirty patients with active RA were treated with 7.5 mg/day prednisolone for six months. During the treatment, changes in morning stiffness duration, arthralgia, Ritchie articular index, Stanford Health Assessment Questionnaire (HAQ), serum C reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels were evaluated every month. BMD was measured at the lumbar spine (L2-L4 anterior - posterior view) and at the femur neck using dual X-ray absorptiometry. BMD was evaluated at baseline and after at the sixth months of the therapy. Results of BMD and clinical and laboratory values were compared at baseline and at the sixth month. Inverse correlations between femur and spine BMD and disease duration, morning stiffness duration, arthralgia, Ritchie articular index, and HAQ scores were found. These correlations, however, did not reach statistical significance. A significant reduction of femur neck BMD (p < 0.05) at the sixth month was found when compared with baseline. According to our results, disease activity affects loss of bone less than low dose prednisolone therapy in RA.