It has been known for some time that mitral annulus calcification is common in end-stage renal disease (ESRD) patients on long-term dialysis, as well as in elderly patients without renal failure. However, a systematic comparison of cardiac calcification in these two types of patients has not yet been made. We examined two-dimensional echocardiograms in 33 patients with ESRD (mean age 66 +/- 10 years) and in 34 other patients with intracardiac calcification but no ESRD (mean age 69 +/- 9 years), with particular attention to precise anatomic location of calcification. Age was not significantly different in the two groups. The incidences of posterior mitral annulus calcification and aortic valve calcification were not significantly different in the ESRD and non-ESRD groups, though mitral annulus calcification tended to be larger in ESRD patients. Basal mitral leaflet calcification and papillary muscle calcification was much more common in the ESRD group. Calcification of intervalvar fibrosa and of tricuspid annulus were noted only in ESRD patients.