The aim of this study was to investigate the role of copper in patients with ankylosing spondilitis (AS). Twenty-nine patients with AS were included in the study and the patients were divided into 2 groups. Group I included 14 patients with systemic hypertension and cardiac abnormalities, Group II consisted of 15 patients with normal cardiac findings. Serum copper levels in Group I patients, measured by flame atomic absorption spectrometry, were 55.0 +/- 3.7 mu g/dl (mean +/- SD) compared with 94.2 +/- 15.5 mu g/dl in a group of matched control subjects. These results suggest that copper deficiency might be an important factor in the development of cardiovascular complications of AS.