The relationship between oxymyoglobin oxidation and lipid oxidation in a bovine muscle homogenate containing FeCl3/ascorbate was examined. Increases (P = 0.05) in lipid oxidation preceded increases in oxymyoglobin oxidation. Lipid oxidation products extracted from an oxidized homogenate had no significant effect on oxymyoglobin oxidation. Increasing lipid oxidation and oxymyoglobin oxidation was associated with a decrease (P = 0.05) in dissolved oxygen. Inclusion of a-tocopherol or Trolox C led to reductions (P = 0.05) in lipid oxidation and oxymyoglobin oxidation, but Trolox C exhibited greater antioxidant potency than a-tocopherol. Hydrogen peroxide had a greater prooxidant effect on oxymyoglobin than the combination of H2O2 and FeCl2. Trolox C inhibited H2O2-induced oxidation of oxymyoglobin. Results support the contention that lipid oxidation is likely to be an important contributor to oxymyoglobin oxidation and meat discoloration.