The steroid hormone status of 27 female patients (15 premenopausal and 12 postmenopausal) and 11 male patients with rheumatoid arthritis (RA) was investigated before and after a clinically significant deterioration in disease activity. In postmenopausal patients the serum level of cortisol decreased significantly with the progression of disease activity. No significant change in the serum levels of oestrone, oestradiol, androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate or prolactin was found within the groups. In premenopausal patients serum cortisol levels also decreased, with progression of disease activity, but this difference did not reach statistical significance. In male patients with RA none of the measured steroid hormone levels changed significantly after exacerbation of disease activity. Our data indicate that the synthesis and/or utilization of cortisol might be abnormal in female patients with active rheumatoid arthritis.