AbstractOxidation in fish during thermal processing was studied by determining volatile production with a static headspace gas chromatographic system. Different processing temperatures and periods were evaluated to simulate conditions of fish industrial treatments. The major volatiles formed included acetaldehyde, propanal, heptane, 2‐ethylfuran, pentanal, and hexanal. Changes in volatile composition were studied for different processing times and temperatures. The method for volatile analyses to determine oxidation in fish muscle was tested by correlation with peroxide value, conjugated diene, and thiobarbituric acid indices. Significant single and multivariate regressions were found between the time of thermal treatment and volatiles produced, showing that the amount of 2‐ethylfuran was the best predictor of oxidative stability in fish.