Two trials were conducted to determine the milk production response to feeding a highly saturated free fatty acid supplement to grazed dairy cows in early lactation. The trials were conducted during spring and autumn, respectively. Sixty-five Friesian cows were supplemented with fat-prills at rates of 0,00 (control), 0,25 and 0,50 kg/d during the first 60 days of lactation, in addition to the usual concentrates fed at levels equivalent to 2% of body-weight in early lactation. Cows in their first lactation did not respond to the fatty-acid supplements. The response of multiparous cows is described by the equation: peak yield (FCM) = 22,44 + 5,88 (kg fat suppl/ d) + 3,52 (body-weight loss/d) (n = 40; R = 0,57; P < 0,01), for the combined trial data. No significant differences were recorded for the butterfat and protein concentrations in the milk. A tendency towards increased weight losses, although non-significant, was recorded for each additional increment of fatty-acid supplement over that of the control cows.