The elbow is the most frequent area of complaint in children and adolescent baseball players. The physical stresses associated with repetitive throwing create extra-ordinary forces, which may affect the normal osteochondral and soft tissue developmental process and are the important factors causing the decrease of competitive power and shortening of life as a baseball player in adolescents. We surveyed the 114 baseball players of middle & high school in Taegu in order to evaluate the prevalance of symptoms and radiologic findings of the elbow and correlation of these findings to career & position of the baseball game. The results were as follows. 1. Of 114 players, 83 were non-pitchers and 31 were pitchers. The mean career was 3.8 years (7 months to 6 years). 2. The 77 players (67.7%) had the pain on their elbow during or after daily exercise. Other clinical symptoms were locking (30.7%), limitation of motion (18.4%), swelling (16.6%) and clicks on motion (10.5%). 3. On the radiogram of the elbow, hypertrophy or separation of medial epicondyle were seen in 34% of players, loose bodies in 17%, hypertrophy of the humerus in 12% and cystic change of the capitellum in 11%. 4. The mean career of symptomatic players was 4.4 years but non-symptomatics was 2.7 years. The mean career of players who had abnormal radiologic findings was 5.1 years but 3.1 years in players who had no abnormal radiologic fingings. 5. Symptoms and pathologic changes were more common in the elbow of pitcher' s group due to throwing frequency & pitching style. 6. Among the 77 players who had any kinds of problem of the elbow, 49 players of them had no experience of visiting hospital. 7. To prevent these injuries of the elbow, the following recommendations were made. First, restrict the number of innings pitched per game. Second, avoid throwing the curve ball in this age group. Third, ensue an adequate warm up period before exercise or rest after games. Fourth, inform parents and coaches of possible harmful nature of excessive throwing.