PURPOSE: To diagnose pelvic mass in women at menacme. METHODS: Case report. PATIENT: D.A.M, aged 31, from Porto Velho, RondÃ´nia. It presents complaint of pain region of left iliac fossa approximately 1 year. Transvaginal ultrasonography revealed left adnexal tumor with negative tumor markers. INTERVENTION: During his stay at the Hospital of Base Ary Pinheiro, a physical examination with a palpable mass was present in the left iliac fossa, irregularly, with a mean and mobile volume, with no signs of ascites and painful palpation, gynecological examination without alterations. Who underwent further examinations, found that she presented a case of pelvic kidney in topography of the left attachment. RESULTS: New ultrasonography and tumor markers were performed, which maintained the hypothesis of pelvic kidney, submitted to excretory urography confirming hypothesis of pelvic kidney and negative markers. CONCLUSION: The importance of the correlation of physical examination and complementary tests, for a faithful diagnosis.