A66-year-oldmanunderwentrobot-assistedlaparoscopicradicalprostatectomyforprostatecancer, atwhichtimelefttransversetesticularectopiawasobserved.Thistime,itwasintroducedforthepurposeofradicalsurgeryforrightinguinalhernia.Ahand-fist-sizedswellingwasobservedfromtheright inguinalregiontothescrotum,butitcouldbeeasilyreturned.AbdominalCTshowedtwotestesinthe rightscrotum.Intraoperativefindingsrevealedahugeherniasacandtwobundlesofvasdeferens,testiculararteries,andveinsinthespermaticcord.Theherniawasrepairedusingameshaftersufficientexfoliation.Thepostoperativecoursewasuneventfulandthepatientwasdischargedonthesecondpostoperative day. We report an extremely rare case of inguinal hernia associated with transverse testicular ectopiainanadult.