PURPOSE: To assess the efficacy and resulting complications of tetracycline sclerotherapy in renal, hepatic, ovarian, and perivesical cysts. MATERIALS AND METHODS: We retrospectively reviewed 23 cases of benign cysts (16 renal, 4 hepatic, 2 ovarian, and 1 perivesical) in 22 patients in whom the condition was diagnosed or confirmed by either ultrasound, CT, or cytology, and who underwent percutaneous tetracycline sclerotherapy. Using a 21-gauge Chiba needle, the target cyst was punctured under ultrasound guidance. Prior to the injection of 1500 mg of tetracycline diluted in 5 ml of normal saline, almost all the cystic content was aspirated, and at the end of the procedure the tetra-cycline was left in the cyst. During a period of between 3 and 22 months, 18 of the 23 cases were followed up. RESULT: In six of the 18 cases followed up, the cysts either decreased in size by 10%, or collapsed completely. In seven cases a collapse of over 50% was noted, and in the remaining five the cyst recurred. In one of these, complete collapse occurred after retreatment at ten months, and the patient with a perivesical cyst underwent surgery six months after recurrence. Thus, treatment was effective (a collapse of at least 50%) in 13 of 18 cases (72.2%). This total of 13 comprised ten of 12 renal cysts (83.3%), two of two ovarian (100%), and one of three hepatic (33.3%). Percutaneous therapy was unsuccessful in five cases (two hepatic cysts, one renal, one para-pelvic and one perivesical). Complications occurring during the procedure or follow-up period included discomfort or mild pain, vomiting, and transient fever, though these subsided within 24 hours. In one patient with severe pain, this subsided after four days. CONCLUSION: As single-shot injection of tetracycline provides safe and effective treatment for renal and ovarian cysts, but for hepatic cysts is unsuccessful.