Fifteen lactating Damascus goats (44 ± 0·8 kg body weight) were used in a completely randomized design to evaluate the supplementation of Chlorella vulgaris microalgae at 0 (Control), 5 (Alg05) and 10 g/goat/day (Alg10) for 12 weeks. Chlorella vulgaris treatments increased feed intake and apparent diet digestibility compared with a control diet. No differences were noted in the ruminal pH and ammonia-N concentrations, but increased concentration of total volatile fatty acids and propionic acid were observed in goats fed with Alg05 and Alg10. Diets of Alg05 and Alg10 increased serum glucose concentration but decreased glutamate-oxaloacetate transaminase, glutamate-pyruvate transaminase and cholesterol concentrations. Additionally, C. vulgaris supplementation moderately increased milk yield, energy corrected milk, total solids, solids not fat and lactose. Feeding Alg05 and Alg10 diets increased milk unsaturated fatty acids with concomitant increases in total conjugated linoleic acid concentrations. It is concluded that the daily inclusion of 5 or 10 g of C. vulgaris in the diets of Damascus goats increased milk yield and positively modified milk fatty acid profile.