Dietary conjugated linoleic acid (CLA) is known to change lipid metabolism in the mammary gland of different animal species and, there has recently been an interest regarding its effect on milk fat synthesis modulation in sows. The objective of this study was to evaluate the effect of CLA on the fatty acid profile of sow milk. Twenty multiparous sows from a commercial line, with a mean body weight (BW) of 200 ± 10 kg were randomly assigned to 1 of the 2 treatments (n = 10/treatment) for 18 d: 1) Control, without CLA; and 2) 1% of CLA (29.9% of trans-10,cis-12 and 29.8% of cis-9,trans-11) mixed in the ration. The diets were formulated to meet the nutritional requirements. The animals were kept in a controlled environment (temperature, humidity, and ventilation) and the CLA treatment was fed from d 7 through d 25 of lactation. Milk samples were collected from all sows at d 25 to evaluate milk fatty acid profile by gas chromatography. Data were analyzed as a complete randomized design using the Mixed Procedure of SAS. Dietary CLA increased the C14:0 (P = 0.003), C18:0 (P < 0.0001), C18:1 trans (P = 0.0004), C20:0 (P < 0.0001), C20:4n-6 (P = 0.03), cis-9,trans-11 CLA (P = 0.0004), and saturated fatty acids (SFA) proportions (P < 0.0001) and reduced the C14:1 (P = 0.0002), C16:1 (P = 0.0001), C18:1 n-9 (P = 0.03), C18:2n-6 (P = 0.03), C18:3n-3 (P = 0.03), and monounsaturated fatty acids (MUFA) (P < 0.0001) proportions. The trans-10,cis-12 isomer was not detectable in the Control treatment, but in the CLA treatment the mean concentration was 0.58%. No alteration in total polyunsaturated fatty acids concentration was observed with the CLA treatment. The distinct shift toward higher deposition of SFA and lower deposition of MUFA indicated a potential downregulation of desaturation by dietary CLA.