The responses of 1700 members (1202 men) of the National Ankylosing Spondylitis Society to a self-administered questionnaire were analyzed. The male:female ratios for primary ankylosing spondylitis, psoriatic spondylitis and spondylitis associated with inflammatory bowel disease were 2.4:1, 3.5:1 and 1:1, respectively. A positive family history was significantly less prevalent in men than women as were hand, elbow, shoulder and knee symptoms. In a parallel radiographic study, 100 men matched for age of onset and disease duration with 50 women demonstrated similar sacroiliac, cervical and hip disease but worse involvement of the lumbar spine.