Concentrations of plasma progesterone, oestradiol-17B, oestrone sulphate, corticosteroids and 13, 14-dihydro-15-keto-prostaglandin F_2α were measured in 12 buffalo cows during the whole length of gestation, around parturition and 15 days postpartum. Concentrations of progesterone and oestradiol-17 β increased slightly during the first 2 (3.5 + 0.9 ng/ml) and 4 (14.8 ±2.1 pg/ml) months of pregnancy. Their values remained fairly constant until the end of ‘pregnancy period when progesterone concentrations decreased significantly (P<0.05) at day 7 (0.9 + 0.1 ng/ml) and oestradiol-17β increased markedly (P<0.01) at day 10 (26.3±2.6 pg/ml) prior to parturition. Progesterone showed basal values (<0.5 ng/ml) from day 4 prepartum to day 15 postpartum while oestradiol-17β concentrations were maximal (82.8 +3.6 pg/ml) during labour reaching basal values (<12 pg/ml) at day 5 postpartum. Concentration of oestrone sulphate remained low (< 140 pg/ml) during the first half of gestation period increasing sharply (P<0.01) thereafter to a peak of 5920 +116.5 pg/ml by 30 hours prepartum and declined to about 50% of its concentrations afterwards reaching basal levels (<80 pg/ml) at day 2.