We investigated the impact of increased alpha-linolenic acid (ALA) dietary levels on its plasma bioavailability and its bioconversion in n-3 long chain poly unsaturated fatty acids (LC-PUFA) during a 60-day kinetics and the oxidative stress potentially associated. Rats were submitted to a normolipidic diet providing 0, 3, 10 and 24% ALA of dietary lipids during a kinetics of 0, 15, 30 and 60 days. The lipid peroxidation and oxidative stress (nitric oxide (NO) contents and catalase (CAT), superoxide dismutase (SOD), gluthation peroxidase (GPx) activities) were studied in the liver and plasma. Data demonstrated that when the diet was deprived in n-3 PUFAs, ALA, (eicosanoic acid) EPA and docosahexaenoic acid (DHA) levels decreased in all lipid fractions of plasma and in red blood cell (RBC) lipids. However when ALA was added in the diet, its bioavailability and its bioconversion in EPA was linearly correlated with the ALA intake (R2=0.98). When the diet provided 10 to 24% ALA in dietary lipids (LA/ALA, 1.6 and 5.5 respectively), ALA and EPA were more broadly packaged in all lipid fractions (triglyceride (TG), cholesterol ester (CE) and free fatty acids (FFA)) of plasma from 15 to 30 days timeframe. However only 3% ALA in the lipid diet was sufficient to promote the maximal bioconversion of ALA in DHA in phospholipid (PL) and TG fractions. Additionally, the improvement of ALA bioconversion in EPA and DHA did not impact the oxidative stress markers wich can limit lipid peroxidation. To conclude, this study demonstrated that 10% ALA in the diet for 15-30 days is the gold diet to promote its bioavailability and its bioconversion in n-3 PUFAs in rat and allowed the greatest levels in plasma and RBCs.