Tendinopathy of the long head of the biceps tendon is a difficult medical issue. Its pathogenesis and etiology is multifactorial and unclear. Tendinopathy is thought to be primarily degenerative in nature, as tendons are characterized by impaired regeneration and healing. Thirty–five patients with preoperatively diagnosed tendinopathy of long head of the biceps tendon were referred to the Orthopedics Department. All patients underwent an arthroscopic–assisted biceps tenodesis or tenotomy. The intra-articular portion of the long head of the biceps tendon was obtained from each of the patients who underwent arthroscopy. A macroscopic and microscopic evaluation of biceps tendon samples revealed degeneration among all specimens. This study demonstrates the prevalence of the degeneration process and the presence of marginal inflammation process in tendinopathy of the long head of biceps tendon. The role, that inflammation process plays in tendinopathy is important in the early phase and gradually becomes secondary to the developing degeneration. The inflammatory cells, occasionally seen in pathological tendons, could be an evidence of re–injury and recent healing response.