The present study provides a detailed overview of the contents of conjugated linoleic acid (CLA) isomers in the most consumed Portuguese CLA-rich foods (milk, butter, yoghurt, cheese, beef and lamb meat), by using silver ion-HPLC. In addition, the contribution of these ruminant-derived foods to the daily intake of CLA isomers was estimated based on Portuguese consumption habits. The total CLA concentration in milk and dairy products ranged from 4·00 mg/g fat in yoghurt to 7·22 mg/g fat in butter, and, regarding meats, from 4·45 mg/g fat in intensively produced beef to 11·29 mg/g fat in lamb meat. The predominant CLA isomers identified in these products were cis-9, trans-11 (59·89–79·21 %) and trans-7, cis-9 (8·04–20·20 %). The average estimated total CLA intake for the Portuguese population was 73·70 mg/d. Milk and cheese are probably the two products with the highest contribution to the final CLA intake, as a result of their high fat content and consumption values. The results also suggested that cis-9, trans-11 and trans-7, cis-9 are the isomers most represented, with, respectively, 76·10 and 12·56 % of the total CLA intake. Being the first detailed report on the contents of total and individual CLA isomers in Portuguese commercial ruminant-derived foods, we further discuss the implication of the results for diet characteristics and human health.