Although non-steroidal anti-inflammatory drugs (NSAIDs) effectively relieve the pain and inflammation of osteoarthritis (OA), there remain suspicions that some, at least, may hinder the organised regrowth of cartilage. Recentin vivoresearch reviewed at the 15th Annual Meeting of the British Society for Rheumatology [Brighton, UK; April 1998] during a symposium entitled ‘Current concepts in arthritis: reviewing the evidence’, suggests that not all NSAIDs are equivalent in this respect.*Aceclofenac has recently been shown to increase cartilage synthesis in chondrocytes cultured from patients with OA and rheumatoid arthritis (RA), but not in those from controls. Some NSAIDs exert an inhibitory effect on cartilage synthesis which can be associated with clinical deterioration, while others are neutral with respect to cartilage formation. The balance between efficacy and tolerability has always been problematic for NSAIDs, particularly as many patients who take these drugs for OA are elderly. The results of a meta-analysis focusing on patient compliance, which were also shown to delegates at the congress, revealed a clear and significant advantage for aceclofenac in terms of compliance and tolerability in patients with OA and RA.