Purpose: We evaluated the efficacy of ultrasonographic examination of the medial collateral ligament injury in elbow joints in the high school male weight lifting athletes. Materials and Methods: The study group (group I) included 15 male weight lifting athletes (average age: 16.8) and the control group (group II) was demographically matched 9 male with no symptoms on their elbow. Both elbow joint was evaluated through physical examination, plain radiograph, valgus stress view and ultrasonography. Results: On plain radiograph, there was no significant differences (3.6 mm, 2.7 mm; p>0.05) for the medial articular distances between both groups. The valgus stress view revealed the significant increase in group I (right, avr. 5.86 mm and 3.52 mm, p<0.01, left, avr. 5.33 mm and 3.64 mm, p<0.01). On ultrasonography, medial joint space was increased in group I (right, avr. 4.66 mm and 3.29 mm, p<0.01, left elbow 4.28 mm and 3.38 mm, p<0.01). The lateral shifting of proximal ulna also increased in group I (right, avr. 0.73 mm and 1.43 mm, p<0.01, left, avr. 0.96 mm and 1.53 mm, p<0.05). The angular deformity were more prevalent in group I. Conclusion: The medial joint space widening and angular deformity was prevalent in male weight lifting athletes. the ultrasonographic examination was useful in evaluating the degree and incidence of the medial collateral ligament injuries.