Detailed medical histories were obtained from 122 consecutive patients with Bechterew's syndrome (ankylosing spondylitis) who had been hospitalized at Oslo Sanitetsforening Rheumatism Hospital. Frequencies of symptoms, age at onset of symptoms and their interrelationships are presented. Low back pain affected more patients than any other symptom and, generally speaking, it started earlier than any other individual symptom. However, any symptom could antedate low back pain. Symptoms preceding low back pain were most frequently reported at a young age, and most often affected the extremities. The presence of psoriasis was associated with an increased frequency of symptoms in the peripheral joints. Acute anterior uveitis and chest stiffness were more common in males than in females. The influence of the selection of patients on the results is discussed.