One hundred patients suffering from ankylosing spondylitis (AS) and one hundred patients suffering from rheumatoid arthritis (RA) were examined by clinical, non-invasive cardiological, radiological and laboratory methods to determine the prevalence of their cardiac and cardiopulmonary disorders. Fourteen patients with AS and 24 patients with RA had several valvular abnormalities. Among the patients not having any valvular abnormality, systolic dysfunction of the myocardium was detectable in 15 and 11 cases respectively, and cor pulmonale was diagnosed in 16 and 7 cases respectively. Conduction disturbances were demonstrated in 17 patients suffering from AS and in 14 patients suffering from RA.