Fat supplementation is an important strategy to increase energy intake of lactating dairy cows. Previous studies have shown that calcium salts of palm fatty acids (CSPF) increased milk and fat yield, but a dose response of CSPF is not well established in dairy cows grazing tropical pastures. Therefore, we evaluated the effects of CSPF on production responses of lactating dairy cows grazing tropical pastures. Forty Holstein × Jersey crossbred cows averaging (mean ± SEM) 20.4 ± 0.35 kg of milk and 20 ± 5 DIM were distributed in a randomized block design to receive one of 4 CSPF levels: Control (no CSPF added); 200 g/d; 400 g/d; and 600 g/d. Dietary treatments were fed for 90 d. Statistical analysis was performed using the MIXED procedure of SAS, with repeated measures, including fixed effects of CSPF and time, and random effects of cow, block, and cow nested in block. Significant differences were declared at P ≤ 0.05, and tendencies at P ≤ 0.10. CSPF linearly increased milk yield (from 22.8 to 26.3 kg/d; P = 0.01), tended to increase fat yield (from 0.79 to 0.88 kg/d; P = 0.08), and did not affect the yields of protein (0.73 kg/d; P = 0.8), casein (0.55 kg/d; P = 0.9), lactose (1.12 kg/d; P = 0.1) and total solids (2.88 kg/d; P = 0.2). For milk component concentrations, CSPF did not affect milk fat (3.38 g/100g; P = 0.3), had a negative linear effect on protein (from 3.30 to 2.82 g/100 g; P < 0.01) and casein (from 2.45 to 2.11; P < 0.01), and had no effect on total solids (11.82%; P = 0.7) and MUN (13.45 mg/dl; P = 0.2). In conclusion, increasing CSPF increased milk and milk fat yield, maintained fat concentration, did not alter milk protein yield and reduced protein concentration.