Ultrasonographic measurements of the urinary bladder in 21 women with systemic sclerosis (SSc) revealed abnormal volume of the bladder in about 65% of patients; 6/21 had a smaller bladder and 7/21 had a larger bladder than the controls. The volume of the remaining urine after miction was higher in 7 patients. Fibrosis of the bladder wall leading to a small rigid bladder and ureteral obstruction resulting in a large bladder with low contractility are suggested as phenomena involved in disturbed function of the urinary bladder in SSc patients. Patients with symptoms lasting more than 14 yrs. were found to have larger premictional volume of the bladder than those with short-lasting disease. No correlation between age, number of deliveries and bladder volume was found.