The aim of this study was to compare the influence of a high alpha-linolenic acid (ALA) diet (linseed diet) and a high linoleic acid (LA) diet (sunflower diet) on performances of pigs, on the dietetical quality of their tissues (adipose tissues and muscles), and on the lipogenic potential of these tissues. Growth and carcass performances, and the lipid content of the tissues were not affected by the diet. Feeding the linseed diet increased the content of n-3 PUFA and decreased the LA/ALA ratios in all the tissues, while the sunflower diet led to an increase in the n-6 PUFA contents. Neither the stearoyl-CoA-desaturase and glucose-6-phosphate-dehydrogenase activities nor the beta-hydroxyacyl-CoA-dehydrogenase activity were affected by the diet. Acetyl-CoA-carboxylase and fatty acid synthase activities were enhanced with the linseed diet in respectively subcutaneous adipose tissue and intermuscular adipose tissue, while malic enzyme activity was decreased in liver and subcutaneous adipose tissue of pigs fed the linseed diet. (C) 2009 Elsevier B.V. All rights reserved.