The purpose of this study was to compare the manifestations of elbow stress due to repetitive valgus forces between the dominant and the non-dominant elbow in 40 uninjured elite team handball players using plain films, stress radiographs, ultrasound, and MRI examination. On comparative plain films generalized bony hypertrophy manifested by increased humeral diameter, and cortical hypertrophy of the humeral shaft of the dominant extremity was observed in all players. A significantly greater difference in medial joint space opening between stressed and unstressed elbows was measured in the dominant elbow compared with the non-dominant elbow (0.41 +/- 0.59 mm). The ultrasonographic findings showed statistically significant bilateral differences in the thickness of the flexor-pronator tendon (0.90 +/- 0.56 mm), extensor tendon (0.96 +/- 0.50 mm), triceps tendon (0.69 +/- 0.27 mm), and medial collateral ligament (0.47 +/- 0.24 mm): the values were systematically higher on the dominant side. US examination showed intra-articular effusions in 67% and small loose bodies in 33.3% of the players, exclusively in dominant elbows. MRI showed joint effusion in the same subjects as US, but loose bodies were only detected in half of the cases found by ultrasound. This study demonstrates that repetitive stress on the dominant extremities of handball players is responsible for physiologic and pathologic changes in the dominant elbow.