Minor components (polar components) and the degree of unsaturation of the fatty acids are the main factors responsible for the oxidative stability of bulk oils and emulsions. The isolated effects of these two factors and their interaction were evaluated in oil–in-water emulsions stored at 32 °C. Samples of coconut, olive, soybean, linseed and fish oils, both full and stripped of their polar components, were used to prepare the emulsions (1% w/w). The maximum concentration of hydroperoxide (LOOHmax) and the rate of formation of hydroperoxides (μmol L−1 h−1) were used to measure the primary products. Hexanal, propanal and malondialdehyde were used to determine the secondary products of the oxidized emulsions containing polyunsaturated fatty acids. LOOHmax varied from 0.16 to 12.75 mmol/kg among the samples. The interaction between the polar components and the degree of unsaturation of the fatty acids was significant (p < 0.001) when the hydroperoxides were evaluated. In general, the degree of unsaturation (β1) and the absence of polar components (β2), respectively, represented 30 and 20% of the contribution to increase the mean oxidation, with the interaction (β12) contribution being more sensitive to the rate of formation of hydroperoxides (16%) than to the LOOHmax (5%). The significance of this interaction suggests that both strategies present synergism and should be applied to improve the oxidative stability of food emulsions.