One hundred consecutive admissions to an acute geriatric unit were examined for clinical and radiographic evidence of osteoarthritis (OA) and articular chondrocalcinosis (ACC). Thirty-four patients had ACC. This was age related, the prevalence rising from 15% in patients aged 65-74 years to 44% in patients over 84 years. The commonly involved joints were the knee (25%), public symphysis (15%), and wrist (9%). No other aetiological factors predisposing to ACC were found. Of the 25 patients with ACC in the knee 7 had no symptoms or signs and no radiographic evidence of OA at that site. However, the combination of ACC and radiographic OA was characterised by an increase in clinical joint disease. Features of inflammation (joint swelling and joint line tenderness) involving the knee, wrist, and elbow were particularly common in ACC. It is concluded that ACC is common in the elderly and is associated with an increased incidence of joint disease.