In dairy animals, high ambient temperature (HTa) decreases eating and subsequently reduces milk production. The objective of this study was to investigate the effects of fat supplementation on eating pattern and milk yield under HTa condition (the average afternoon THI = 85.2 ± 0.49). At approximately 1 mo before parturition, 10 crossbred dairy goats were divided into 2 groups (n = 5 each) including control (CNT, 31.4 ± 3.0 kg BW) and 2% coconut oil supplementation (CoO, 30.0 ± 2.0 kg BW). Both experimental formulations were isoenergetic and isonitrogenous (37.7% DM and 1.7 Mcal NEL/kg). During the late gestation, coconut oil supplementation did not affect daily dry matter intake (DMI) as compared with CNT (0.9 ± 0.1 and 0.8 ± 0.1 kg/d, P > 0.05). However, the light phase DMI (from 0700 to 1800) of CoO group was higher than from CNT group (0.8 ± 0.1 and 0.6 ± 0.1 kg/d, P < 0.05). During lactation period, there was again no effect of coconut oil on DMI. However, cumulative milk yield as 4%FCM (5 wk) from the CoO group tend to be lower than from CNT group (CNT; 61.9 ± 1.9 and CoO; 49.7 ± 7.5 kg, P = 0.059). The ratio of daily 4%FCM to DMI, feed efficient for milk (FE_milk), revealed a significant lower FE_milk in CoO than in CNT groups (1.4 ± 0.1 and 1.1 ± 0.1 kg of milk/kg of DMI, P < 0.05). The concentrations of protein (3.0 ± 0.1 and 3.6 ± 0.2%) and fat (3.8 ± 0.2 and 4.9 ± 0.2%), but not lactose (4.6 ± 0.1 and 4.9 ± 0.1%), from CoO group were higher than from CNT group. There were no effects of total-tract nutrient digestibility (74.5 ± 2.4 and 70.2 ± 3.6%). The plasma concentration of glucose, free fatty acid and β-hydroxy butyrate were not different between groups. In conclusion, the present experiment suggested that an attempt to increase energy density by supplementation with 2% coconut oil did not affect DMI, nutrient digestibility and plasma metabolites. However, feeding with 2% coconut oil formulation before parturition and during lactation produced negative effect on MY and FE_milk. The lower MY and the higher milk protein and fat apparently came from the direct effect of coconut oil per se.