Extracorporeal shock-wave lithotripsy (ESWL) is a safe and widespread modality for the treatment of renal stones. Although rarely used for treatment of subcapsular hematoma of the kidney, this procedure may sometimes be required in critical case for possible renal loss. This study investigated 10 subcapsular hematomas that were encountered during a 10-year period using ESWL treatment in patients with renal stones. This history revealed eight with hypertension, four with urinary tract infection (UTI), two with diabetes mellitus (DM) and 1 with peptic ulcer. None of the patients died. One Dm patient with coexisting UTI underwent nephrectomy due to the occurrence of perirenal abscess. Age older than 50 years and multiple stones might be risk fac-tors of the occurrence of perirenal hematoma after ESWL.(J Urol R.O.C., 10:164-167,1999)