The effects of α‐, γ/δ, and δ‐tocopherol concentrates (0.2–2.0%) alone and in combination with ascorbyl palmitate (0.1%) and lecithin (0.5%) on oxidative stability and flavor of fish oil were studied. Stability was assessed on oil stored in air at 20°C by peroxide value (PV) and off‐flavor formation. Polymer content, para‐anisidine value, and conjugation were used to characterize selected samples. When used alone, the protective effect of the tocopherols, as measured by PV, was δ≫γ/δ≫α, especially at the 2% concentration. Binary systems of ascorbyl palmitate‐lecithin and lecithin‐γ/δ or‐δ‐tocopherol were strongly synergistic in delaying peroxidation. The ternary blends provided the greatest protection against autoxidation. Refined fish oil with 2% δ‐tocopherol, 0.1% ascorbyl palmitate, and 0.5% lecithin showed no significant peroxidation at 20°C over a period of 6 mon. The original antioxidant effect noted for the ternary systems in delaying peroxidation was not reflected in improved flavor stability. Off‐flavors developed within 3 wk, making the oils unsuitable for use at high concentrations in ambient products that are unprotected from air.