Conjugated linoleic acid (CLA) trans-10,cis-12 is able to cause milk fat depression (MFD) in lactating cows, goats and ewes. The objective of this study was evaluate if stearic acid (C18:0) is able to overcome the MFD caused by CLA trans-10,cis-12. Twenty-eight Lacaune sheep (36 ± 3 DIM; 73 ± 8.1 kg BW) were used in a completely randomized design (n = 7/treatment) for 21 d (7 d of adaptation and 14 d of data collection). The animals were submitted to 4 treatments: a) Control (no CLA or C18:0); b) CLA (27 g of CLA, 29.9% of trans-10,cis-12 orally fed); c) C18:0 (32 g of C18:0, 87%, mixed to the concentrate) and; d) CLAC18:0. Milk yield was measured and milk samples, individually, were obtained each 2 d. The data were analyzed using the MIXED procedure of the SAS, using treatments as fixed effect and the animal as random. Compared with Control, CLA and CLAC18:0 reduced milk fat content by 12 (P = 0.0003) and 14% (P = 0.0001), respectively, with no difference between CLA and CLAC18:0 (P = 0.50). The lactose content was increased in CLA compared with C18:0 and CLAC18:0, respectively, in 2 (P = 0.05) and 7% (P = 0.0001), and reduced in 6% for CLAC18:0 compared with Control (P = 0.0001). The CLA and CLAC18:0, in comparison to Control decreased the content of total solids in of 4 (P = 0.011) and 7% (P = 0.0001). There was no difference on milk and protein yield. Overall, C18:0 combined with CLA trans-10,cis-12 was not able to inhibit CLA-induced MFD.