We present our experience with 7 patients who developed injection site granuloma with leuprorelin acetate injection. Although isolated case reports exist, this is the largest collection of cases from a single center. The exact mechanism of the granuloma formation is not well understood, although theories are associated with the vehicle used for injection. Our discussion focuses on the nature of the granuloma formation and its etiology. The reaction appears to be more common with leuprorelin acetate than with other forms of luteinizing hormone-releasing hormone analogues. © 2007 Elsevier Inc. All rights reserved.