Objectives: To compare our extended experience with high submuscular (HSM) reservoir placement to traditional space of Retzius (SOR) placement and to present our current, refined ‘Five-Step’ technique (FST) for HSM placement. Patients and Methods: Data were retrospectively collected on patients undergoing inflatable penile prosthesis (IPP) placement between January 2009 and June 2019. Re-operative cases were excluded. Reservoir-related complications and subsequent revisions were compared between SOR (2009–2012) and HSM reservoir groups (2012–2019). HSM patients were subdivided into two cohorts: ‘Initial Technique’ (2012–2014) and FST (2014–2019). The refined FST protocol was developed in 2014 to optimise outcomes and includes the following steps: (i) Position and Access; (ii) Develop Lower HSM Pocket; (iii) Develop Upper HSM Pocket; (iv) Reservoir Delivery (fill and fine-tune); (v) Confirm and Connect. Results: Between January 2009 and June 2019, 733 total IPP procedures (586 HSM, 147 SOR) were performed by a single surgeon at our institution, 561 of which were virgin cases (430 HSM, 131 SOR) and included in this analysis. Overall, surgical revision was required in 10/430 (2.3%) HSM cases (one delayed bowel obstruction, nine herniations) and six of 131 (4.6%) SOR cases (one bladder erosion, two vascular injuries, and three herniations, P = 0.22). When comparing the FST to the Initial Technique, we noted a significant decrease in complications requiring surgical revision (P = 0.01). Among 133 cases performed with the Initial Technique, seven (5.3%) required surgical revision (one bowel obstruction after placement into the peritoneal cavity, six herniations). Among 297 FST cases, three (1.0%) required revision, all due to herniation. Conclusion: HSM placement of IPP reservoirs is a safe alternative to traditional SOR placement. Major deep pelvic reservoir complications were minimised using our current refined FST.