['To determine if bilateral S3 lead placement during the stage I trial period improves the "success" rate for advancing to stage II (permanent) sacral neuromodulator placement.', 'A retrospective chart review of 124 (20 male and 104 female) patients undergoing stage I sacral neuromodulation (InterStim, Medtronic, Minneapolis, Minnesota) implantation for the treatment of refractory voiding dysfunction was performed. Patients were divided into two cohorts based on unilateral versus bilateral stage I lead placement in the S3 foramina. Both groups were then evaluated and compared with regards to overall "success", defined as progression from stage I to stage II placement.', 'Fifty-five (44%) patients underwent unilateral stage I lead placement and 69 (56%) received bilateral S3 leads. Successful stage I trials were reported in 32/55 (58%) and 53/69 (76%) of unilateral and bilateral cohorts, respectively (P = 0.03). Five wound infections were reported-2 (3.6%) following unilateral and 3 (4.3%) after bilateral stage I lead placement. No other complications were encountered.'] Do unilateral versus bilateral stage I neuromodulator lead placement for the treatment of refractory voiding dysfunction?