Objectives: To compare the efficacy of intrathecal fentanyl and dorsal penile nerve block for postoperative pain management in patients undergoing inflatable penile prosthesis (IPP). Patients and methods: A prospective single-center study included 80 patients amenable to IPP. Patients were divided equally into two groups. Group I included 40 patients who were managed with spinal anesthesia with intrathecal fentanyl before undergoing IPP. Group II comprised 40 patients who received spinal anesthesia with dorsal penile block before IPP. Study groups were compared regarding postoperative VAS (Visual Analog Scale) scores, total narcotics consumption, patient satisfaction levels, and perioperative complications. Results: The study groups were comparable regarding baseline patients’ criteria. The operative time was comparable between the study groups, with group I and group II having respective median times of 64 minutes (interquartile range: 55-78) and 67 minutes (interquartile range: 56-81) (p = 0.65). Additionally, both groups demonstrated similar distributions in IPP implant cylinder and reservoir size (p = 0.9). Postoperative pain was higher in group I, with a statistically significant difference (p < 0.001). Eight patients in group I (20%) called the physician’s office asking for pain medication, compared to two patients in group II (5%) (p = 0.04). 85% of patients in group II were highly satisfied compared to 50 % in group I (p = 0.003). We reported a 5% complication rate in group I compared to 2.5% in group II (p = 0.6). Conclusions: The present study found that the dorsal penile nerve block offers superior postoperative pain control and patient satisfaction compared to intrathecal fentanyl for patients undergoing inflatable penile prosthesis insertion.