The effects of (n-3) polyunsaturated fatty acids (PUFA) diet deficiency on learning, electroretinogram and retinal fatty acid composition were assessed for the first time in OF1 mice. Pups fed the same diets (deficient in alpha-linolenic acid or a control) as their dams were used aged 7 weeks for passive avoidance test and fatty acid analysis of retinal phospholipids. Visual function was measured by electroretinography in 4- and 7-week-old mice. The (n-3) PUFA-deficient diet significantly decreased learning performance and retinal docosahexaenoic acid level in adult mice. The electroretinogram showed a significant alteration of b-wave amplitude in deficient mice at 4 weeks but not at 7 weeks. These results show that learning deficits in mice fed a diet deficient in (n-3) PUFA were not due to visual alteration.