Background There are limited options for men with large benign prostates (>150cc) and bladder outflow obstruction due to benign prostatic hyperplasia (BPH). Management options include surgery (open or minimal access) and endoscopic procedures. There is a paucity of literature on outcomes for prostates >150cc. Methods In this case series we describe a step-by-step, illustrated, modified extra-peritoneal technique of laparoscopic prostatectomy with preservation of the posterior prostatic urethra. This involves creation of extra-peritoneal space, transverse incision of prostate capsule, progressive adenoma dissection, resection, and closure of the capsule. Results Ten patients underwent this procedure between 2015 and 2019. The mean age was 72.4 years and mean prostate size was 215.5cc. Mean procedure duration was 200 min and there were no intraoperative complications. Most patients were discharged on postoperative day 1. Mean intraoperative blood loss was 120 ml with no patient requiring blood transfusion. At follow up (mean 37 months) no patients had residual symptoms of BPH. Conclusion We describe a novel extraperitoneal laparoscopic technique for benign prostates of >150cc with very good outcomes. The transferability of this technique to centres with laparoscopic expertise at minimal extra cost and future adaptability in the robotic setting are some of the advantages of this technique.