Retroperitoneal pelvic lymphoceles are one of the most common complications following renal transplantation, and usually present with a palpable mass, ipsilateral leg edema, hydronephrosis caused by ureteral obstruction, decreased renal function and cutaneous lymphatic fistula. However, lymphocele rarely causes acute urinary retention. In this study, we describe a case of a patient who developed acute urinary retention after renal transplantation mimicking urethral injury. When a transplanted patient demonstrates the inability to void, one should consider bladder outlet obstruction resulting from lymphocele as a possible cause.