Objective: The purpose of this study was to describe our experience with ultrasound-guided aspiration of postoperative pelvic lymphocysts followed by intracavitary minocycline injection as sclerotherapy. Patients and Methods: From 1997 to 2003, patients who developed either symptomatic or persistent lymphocyst after pelvic lymphadenectomy for gynecological malignancy were recruited in this study. All of the lymphocysts were palpable and were further examined by ultrasonography. Percutaneous ultrasound-guided needle aspiration of the lymphocyst was performed and then immediately followed by a single-dose injection of minocycline into the collapsed cavity. Follow-up was conducted every 4 weeks with pelvic examination and ultrasonography. Results: Nineteen patients with a total of 21 pelvic lymphocysts underwent this procedure. The median size of the lymphocysts was 6 cm in diameter (range, 4–9 cm). Fifteen patients received 1 treatment, 3 received 2, and 1 patient with bilateral lymphocysts received 3 treatments. Complete resolution occurred in 14 patients (74%), and the other 5 patients (26%) had partial resolution with the volume of the lymphocyst decreasing at least 50%. For the 14 patients with complete resolution, the median time from treatment to disappearance of the lymphocyst was 3 months (range, 1–10 months), and none of them developed recurrence during the average follow-up period of 40 months (range, 2–62 months). No significant complication occurred with this procedure except for transient mild to moderate pelvic pain. Discussion: Minocycline sclerotherapy seems to be a simple and safe method with a satisfactory success rate in treating lymphocysts which develop after pelvic lymphadenectomy. It can be performed in an outpatient setting and can be repeated if necessary. This procedure may be considered as the initial treatment modality for patients suffering from symptomatic or persistent lymphocysts after radical gynecological surgery.