Objective: To evaluate the efficacy of removal of a "lost" intrauterine device (IUD) with the use of a cylindrical brush. Methods: Women aged 25-43 years with so-called "lost" IUD, in whom the string was indiscernible, were enrolled in the study. During gynecologic examination, a cylindrical brush was rotated in the cervical canal until the device was extracted by a rotating motion. No antibiotics were used after removal of the IUD with the cylindrical brush. Results: Twenty-seven women whose IUD could not be removed from the uterine cavity because of an indiscernible string were referred for a trial of IUD removal. All patients had used a plastic, copper-releasing IUD. Before admission, they had undergone an attempt at IUD removal by their physician using either a hook or clamp. In 24 patients who were referred to our center, the IUD was removed by using a cylindrical brush to view the string. The IUD was removed by hysteroscopy in three cases, in two of which no string was found. Conclusion: A cylindrical brush can be used safely as an adjunct to remove an IUD and is a simple method that may be performed before another invasive procedure is attempted. (Obstet Gynecol 1996;87:785-6).