Estimation of sex when investigating subadult skeletal remains is largely problematic because of unreliable and inaccurate results. Despite the limitations encountered with skeletal material, the medical literature clearly demonstrates differences between males and females in utero that persist through life. The current study investigates sexual dimorphism in the long bones of the humerus and femur for individuals between birth and 1 year of age. A radiographic sample amassed from Erie County Medical Examiner's office includes 85 femoral and 45 humeral images for analysis in relation to sex. Measurements for lengths and breadths were collected through tpsDig software. Discriminant analysis proved to be the most successful method, with error rates of 3 percent when utilizing maximum breadth at midshaft of the femur and 11 percent with humerus maximum distal breadth. This research demonstrates that it is possible to correctly classify sex of unknown subadult remains when comparing them to a known sample. Abstract published by arrangement with John Wiley & Sons.