Nonsteroidal antiinflammatory drugs (NSAIDs) are used in the therapy of both inflammatory and degenerative diseases of the locomotor system. Due to the relatively high occurrence of adverse effects, mainly on the gastrointestinal tract, NSAID therapy often has to be discontinued. Studies focusing on long-term NSAID therapy end points are rare. Two hundred patients presenting with classic rheumatic diseases (osteoarthritis, n = 50; rheumatoid arthritis, n = 130; ankylosing spondylitis, n = 20) were given a daily dose of 200 mg sustained-release flurbiprofen (flurbiprofen SR). The aim of the study was to assess the results of a 6-month treatment. This open therapeutic study was carried out in 10 rheumatological outpatient departments in the Slovak Republic with 20 patients from each department. The patients were monitored monthly during the 6 months of treatment. The group comprised 71% females with an average age of 52.7 years (range 22-72 years). The degree of the disease activity was assessed at the start of the study as moderate (68%) for all groups. Average disease duration was 10.4 years (0.4-35 years). Most patients had previously been treated with other NSAIDs. A total of 151 patients (75.5%) successfully completed the 6-month therapy with flurbiprofen; 49 patients (24.5%) withdrew from the treatment prematurely, most of them at an early stage (23 during the first month, 11 during the second month, five during the third and fourth months each, three during the fifth month and two during the sixth month). The reasons were lack of efficacy in 10 patients and adverse effects (mostly mild to moderate gastrointestinal intolerance) in 26. The remaining 13 patients gave other reasons for withdrawal. No predictive factors could be identified on comparing the basic demographic data of patients who completed the course of treatment with those who withdrew from therapy. In conclusion, flurbiprofen SR given in a single daily dose of 200 mg is an effective and relatively well tolerated NSAID, which is suitable for the long-term treatment of most patients with chronic arthritic conditions.