Abstract Background: The morphometry of the scapula exhibits sexual dimorphism, which makes it crucial for sex determination in forensic contexts and guides orthopedic surgeons in the management of shoulder girdle fractures. Objective: This study aimed to establish population-specific discriminant formulas for sex determination using the scapula length from radiographs. Materials and Methods: This observational cross-sectional study retrospectively analyzed 200 postero-anterior chest radiographs (113 males and 87 females) from a referral hospital in Delta State, Nigeria. Inclusion criteria comprised fully ossified scapulae in patients aged 25–60 years. Scapula length was measured using digital calipers, and statistical analyses, including discriminant function analysis, were performed to create population-specific equations for sex prediction. Results: Males exhibited significantly longer scapulae than females. The right scapula length was longer and demonstrated higher overall accuracy (78.5%) in sex determination than the left scapula (75.0%). Combining right and left scapula lengths increased the accuracy to 83.0%. Conclusion: The study provides population-specific normative values for scapula length and highlights the sexual dimorphism of the scapula length. The length of the right scapula was more accurate in predicting sex (78.5%) and when combined with that of the left scapula, the accuracy increased (83.0%).