100 patients with several clinical and suspicious radiological symptoms of Bechterev's disease (Institute of Rheumatology Moscow) and 100 patients with the clinical symptoms of Bechterev's disease without radiological symptoms of a sacroiliacal arthritis (Medico-Policlinical Institute Leipzig) have been examined within a common research programme since 1976 and analysed concerning the frequency of the complaints as well as of clinical symptoms at the beginning of the disease. The main complaints at the beginning of Bechterev's disease are nocturnal pains in the lumbosacral region, pains in the joints, in which cases 50% of the patients spoke of swellings of the joints. 42% of the patients complained of the feeling of the morning rigidity in the lumbar spinal column and 22% spoke of increased temperatures. In 9--10% of our patients an iritis was diagnosed at the beginning of the disease.