The prevalence of articular chondrocalcinosis was studied in a group of 100 patients with seropositive rheumatoid arthritis (RA). Articular chondrocalcinosis was observed less frequently (3%) than in a control group (19%) of 221 age and sex matched patients with low back pain or extraarticular rheumatism. This difference is statistically significant (p less than 0.001). Articular chondrocalcinosis occurred in the older patients with RA, and was observed in those with the shortest duration of the disease.