OBJECTIVE To determine the value of magnetic resonance (MR) imaging in the clinical management of chronic refractory lateral epicondylitis. METHODS Coronal three-dimensional Fourier transform, multiplanar gradient-recalled-echo, and fat-suppressed sagittal images were obtained in 33 patients. Twenty of these patients underwent surgical débridement and/or primary tendon repair and were included in the correlative study. Surgical and pathologic reports were reviewed to determine the location and gross characteristics of the tissue. RESULTS Findings at MR imaging correlated with the surgical findings of primary degeneration of the extensor carpi radialis brevis (n = 20). Histopathologic examination demonstrated neovascularization, disruption of collagen, and mucoid degeneration without inflammation. CONCLUSIONS The use of MR imaging in patients with recalcitrant lateral epicondylitis assists in surgical planning. The definition of tendon degeneration and degree of tear, as depicted on MR images, correlate well with surgical and histologic findings.