Background: The treatment of bilateral complex renal stones is a tough challenge for urologists. This study aimed to evaluate the efficiency and safety of bilateral ultrasonography-guided multi-tract percutaneous nephrolithotomy (PCNL) combined with EMS lithotripsy for the treatment of such cases. Methods: Twenty-seven patients suffering from bilateral complex renal calculi underwent t bilateral multi-tract PCNL. The PCNL began with the establishment of percutaneous nephrostomy access, which was achieved under ultrasound guidance followed by stone fragment and removal by EMS lithotripsy. The same processes were then performed on the ipsilateral and contralateral renal units until the operation terminated. Sheaths left in situ to provide the tracts for the two-stage and the three-stage PCNL procedures. Peri-and postoperative clinical data were collected and analysed. Results: Renal stones of both sides were completely cleared within three PCNL sessions in 24 cases. Among them, four, thirteen, and seven cases underwent single, second-stage and third-stage procedures, respectively. The total stone-free rate was 88.9%. Three patients failed to receive complete stone clearance. Mean operation time was 78.7 (26-124) min, the mean estimated blood loss was 97.3 (30-250) ml, and the mean length of hospital stay was 18 (10-31) days. No patient required blood transfusion and postoperative fever occurred in 6 cases. Within the follow-up period, stone recurrence occurred in 6 patients. Conclusions: Ultrasonography-guided multi-tract PCNL using EMS is an efficient method for the treatment of complex renal calculi. According to our experience, it is safe to make multiple tracts on both sides simultaneously.