In a prior in vivo experiment, daily injection of the putative Peroxisome Proliferator-activated Receptor gamma (PPARγ) agonist 2,4-thiazolidinedione (TZD) in dairy goats with less-then-adequate nutritional status did not affect milk fat. In the present experiment, we tested the hypothesis that PPAR$\gamma#$ activation affects milk fat synthesis in goats with adequate nutritional status. Saanen multiparous goats in early-mid lactation received a diet that met NRC requirements and were injected daily with 8 mg/kg BW of TZD (n = 6) or saline (n = 6; CTR) for 3 wk. Blood and milk samples were collected at 9 time points during the experiment. Blood samples were used to measure several parameters related to metabolism and inflammation. Milk yield and milk components including fatty acid profile were assessed. Expression of fatty acid metabolism-related genes was measured via RTqPCR in adipose tissue and mammary epithelial cells (MEC) isolated from milk. Adipocytes size was assessed by histological analysis. Data were analyzed by GLIMMIX of SAS with TZD and time and their interaction as main effects and goats as random effect. Decreased (P < 0.05) plasmatic NEFA, NEFA/Albumin, BHBA, and fatty acids and increased (P < 0.05) glucose were detected in TZD. Milk yield and milk fat were not affected by the treatment. TZD increased (P < 0.05) the size of adipocytes and increased (P < 0.05) the expression of genes related to glucose metabolism and insulin signaling such as GAPDH and IRS1 and tended (P ≤ 0.09) to increase SLC2A4 and to decrease the expression of CD36 and YWHAZ, a putative inhibitor of insulin signaling. The expression of SCD1 was decreased (P = 0.06) in MEC by TZD treatment. In milk TZD increased (P < 0.05) the proportion of long and very long chain fatty acids of dietary origin, such as C18:0, several 18:1 isomers, all-trans C18:3, and C22:0. No other parameters were affected by TZD. Results failed to support the hypothesis that TZD activates PPARγ in MEC of animals in good nutritional condition. TZD had minimal effect on milk fat synthesis but milk fat production was maintained at the level of CTR despite a lower availability of NEFA and a possible larger de-novo fatty acid synthesis using glucose in adipose tissue.