Impaired wound healing in humans under psychological stress and the positive effects of antidepressant drugs on wound healing were also shown in the literature. However, there are currently no studies regarding the effects of antidepressant drugs on tendon healing. The aim of this study was to compare tendon healing under normal conditions versus social stress. We also aimed to perform a histological and biomechanical analysis of the effects of the antidepressant drug fluoxetine on tendon healing. Sixty Sprague Dawley rats were divided into six groups. A social stress regimen was used to stress the rats. The use of fluoxetine in the social stress group yielded significantly better biomechanical results and the collagen organizations of the fluoxetine group were more similar to the normal tendon collagen organization. Fluoxetine seems to inhibit the negative effects of stress on tendon healing and seems to improve tendon healing.