In this case report, we describe a 70-year-old white man with prostate-specific antigen of 1.8 ng/mL, clinical stage T2bN0M0, Gleason 4+5=9 prostate cancer who developed an unusual side effect from leuprolide acetate as part of his androgen deprivation therapy. The gene discussed is KLK3; the disease is prostate carcinoma.