The aim of this study was to investigate whether oxidative stress contributes to the development of atrophy in immobilized muscles, and, under this assumption, whether the administration of an antioxidant has beneficial effects to attenuate immobilization atrophy. One hindlimb of rats was immobilized for eight days, the contralateral leg served as control. One experimental group was supplemented with vitamin E. In the soleus muscle, the glutathione content as an indicator for oxidative stress was measured, and muscle fiber diameters were evaluated to estimate muscle atrophy. The biochemical results indicate no pronounced oxidative stress in the immobilized muscles and even less oxidative stress in the vitamin E supplemented muscles (with and without immobilization). Eight days of immobilization lead to a 35% atrophy, while with vitamin E the muscles atrophied only by 12%. This difference can be attributed to the action of vitamin E as a scavenger for free radicals and, on the other hand, to an atrophy promoting effect of oxidative stress. Oxidative stress is hypothesized to exist during the initial phase, but to disappear after some days of immobilization. It is suggested that oxidative stress plays a role in initiating muscle atrophy, and supplementation of vitamin E prior to and during the early phase of immobilization is recommended. Moreover, such may also be useful during remobilization to avoid additional oxidative stress with rehabilitative exercise.