This study aimed at investigating changes in the fatty acid (FA) profile and conjugated linoleic acid (CLA) concentration of milk fat during lactation from goats managed in a semi-intensive production system, which consisted of grazing on a woody and herbaceous pasture with the supplementation of mixed concentrate and vetch hay. A total of 21 lactating goats were used. Milk samples were collected at different periods (25 April, 29 June, 25 August and 4 October) during lactation and analysed for their chemical composition and FA profile. The most abundant FA in the milk fat of goats was palmitic (06:0) acid, followed by oleic (C18:1 n-9), stearic (C18:0), capric (C10:0) and myristic (04:0) acids. These acids accounted for about 88% of the total milk FA of goats in all sampling periods. The two medium chain FA; capric (P=0.0001) and lauric (C12:0; P=0.0014) acid were affected by the sampling period, whereas myristic (P=0.4469) and palmitic (P=0.4418) acids did not change. Stearic (P=0.0128), oleic (P=0.0001), linoleic (C18:2; P=0.0088) and linolenic (C18:3; P=0.0001) acids also exhibited significant variations between the sampling periods. However, the CLA (C18:2 c9, t11 and C18:2 00, c12) contents of milk fat did not change during the entire study regardless of the sampling period (P=0.2448). Milk fatty acid composition of goats, which meet a major part of their nutrient requirements through grazing or browsing in a natural pasture, shows a seasonal variation with milk fat in summer representing a better fatty acid profile for product quality.