Complete ischemia in the left hindlimb was maintained for 3.5 h in 16 rats randomized into two equal groups. One group served as control, the other was treated with pentoxifylline before, during and after the ischemic period. The animals were killed 72 h later, and the anterior tibial muscles were prepared for histological investigation. The most severely damaged muscles had a central core with complete necrosis of all muscle fibers, disintegrated capillaries and no macrophage infiltration. This zone, which was called the area of no resorption, was surrounded by an area of incomplete necrosis with partly resorbed muscle fibers, intact capillaries and marked macrophage infiltration. The muscles were completely intact only in a narrow subfascial zone. The total areas of necrosis and the areas of no resorption were measured as percent of the cross-sectional area of each muscle. There was extensive necrosis in both groups. The infarcted area was 93% in the control group and 89% in the treated group (NS). The corresponding areas of no resorption were 23 and 6% (p = 0.01). The study indicates that pentoxifylline has some protective effect on ischemic muscle damage. However, this effect is marginal compared to moderate hypothermic treatment.