Recent concern about the adverse effects and relative risks of anti- inflammatory therapies has been such that another meeting was organized in the highly successful series of meetings on this topic. Adverse effects of anti-rheumatic and anti-inflammatory drugs are of major concern to all involved in the prescription, care and management of rheumatic and other patients receiving these important drugs. The IVth International Meeting on Side-Effects of Anti-Inflammatory Drugs, held in Sheffield, UK, 7-9 August 1995, afforded a unique opportunity to hear the latest information and views on issues concerning the development of adverse effects from these drugs, the management of these effects, and the development of safer therapies. In addition to discussions on the safety relative to efficacy of established non-steroidal and steroidal anti-inflammatory drugs and disease-modifying agents, there was detailed consideration of the novel cyclo-oxygenase-2 selective NSAIDs which have recently been developed and introduced to the clinic. Also, the side effects from therapy with biologics, notably monoclonal antibodies and oral tolerance therapies, were considered. Among the other highlights in the programme were: Clinico-epidemiological studies on the adverse effects relative to use/efficacy of established and new anti-rheumatic drugs. Procedures for reducing the gastrointestinal adverse effects. Mechanisms and clinical significance of adverse effects in the gastrointestinal tract, liver, kidney, articular joints, skin and other organs from NSAIDs. Clinical status and mechanisms of action of the newer (third generation) of NSAIDs (e.g. etodolac, nabumetone, meloxicam). Medico-legal aspects of adverse effects from anti-rheumatic drugs. The concept of `conditional pharmacology' or the disease-dependence of the toxicological and pharmacological activity of the anti-inflammatory drugs. The papers in this book were selected from those presented at the meeting.