Streptozotocin (STZ)-induced diabetes in mice progresses with decreased desaturase activities and alterations in the metabolism of essential fatty acids (EFA). OBJECTIVE Based on our previous studies with soybean oil that ameliorated the STZ damage in mice, we tested here the accountability of its main EFA components, i.e. linoleic acid (LA) and alpha linolenic acid (ALA), in the prevention of pancreas damage and Δ6 desaturase decrease. METHODS Seven days after injection with STZ and EFA gavage, ICR mice were sacrificed. Plasma glucose and insulin levels, pancreas histology and liver fatty acid desaturases were analysed. RESULTS EFA reduced pancreas damage, insulin and glucose plasma levels and restored Δ6 desaturase activity and mRNA expression levels. CONCLUSIONS By reducing pancreas damage, EFA ameliorated insulin levels, Δ6 desaturase and fatty acid metabolism. LA further enhanced Fads2 promoter activity. CONCLUSIONS EFA ameliorate STZ induced diabetes in mice.