OBJECTIVE. We assessed the ability of high-resolution sonography to reveal the size and echogenicity of the anterior bundle of the normal medial collateral ligament of the elbow in cadavers and uninjured male volunteers. MATERIALS AND METHODS. The anterior bundle of the medial collateral ligament in five cadaveric elbows was imaged and injected with contrast material by experienced musculoskeletal radiologists using a 12-MHz linear array transducer. Immediate ligament dissection was performed. The bilateral ligaments in 30 healthy 21- to 34-year-old male volunteers were imaged with gravitational stress. Of these, five randomly selected subjects also received approximately 5 lb (11.3 kg) of applied stress. RESULTS. Contrast material was injected directly into all five cadaveric ligaments. The anterior bundle of the medial collateral ligament in all 30 asymptomatic male volunteers was hyperechoic in comparison with surrounding muscle and had a fibrillar pattern and fanlike shape. Its mean dimensions were 2.6 ± 0.31 × 2.2 ± 0.47 × 4.0 ± 0.88 mm on the right and 2.6 ± 0.36 × 2.1 ± 0.42 × 4.0 ± 0.86 mm on the left, in longitudinal short, transverse short, and transverse long axes, respectively. Differences in ligament measurements in sidedness, stress application, and hand dominance did not approach statistical (Bonferroni corrected, p > 0.01) or clinical (all differences, <0.2 mm) significance. CONCLUSION. Radiologists can accurately use sonography to identify and measure the size of the anterior bundle of the normal medial collateral ligament of the elbow. These baseline parameters for the normal ligament may prove useful when evaluating the injured ligament.