Background: The greater sciatic notch is a critical anatomical landmark in the human pelvis, and its morphology exhibits sexual dimorphism with females exhibiting a wider and deeper notch, and longer anterior and posterior segments. These results have implications for forensic anthropology, orthopedic surgery and obstetrics, particularly in sex determination from skeletal remains and surgical approaches to the pelvis. This study investigated the sexual dimorphism of the greater sciatic notch (GSN) in adult human pelvises to determine its reliability for sex determination. Methods: The study was conducted for period of 3 year from 2016 to 2019 after obtaining institutional board clearance. Forty pelvic bones (20 male, 20 female) were analyzed, and six parameters were measured: width, depth, anterior segment, posterior segment, total angle, and posterior angle of the GSN. Results: The results showed that females have greater values in most parameters, with significant mean differences in width (10.95 mm), anterior segment (8.15 mm), posterior segment (4.34 mm), and posterior angle (8.90 degrees) The results showed statistically significant differences (p < 0.05) between males and females in width, anterior segment, and posterior angle, with females having greater values. The width of the GSN was found to be the most reliable parameter for sex determination, with a mean difference of 11.2mm between males and females. Conclusion: The study concludes that the GSN is a useful parameter for sex determination in forensic anthropology and osteology, particularly when other skeletal elements are unavailable or damaged. The findings support the use of GSN measurements in sex determination, with potential applications in human identification and forensic investigations.