Twenty-eight of lactating Friesian cows about 5 – 10 years and 575 – 725 kg weight had dystocia and single-calf parturition were used in the present study. The experimental animal were divided into four groups (7 animals /group). Cows in the first group were administrated with 10 ml of saline solution (0.9 NaCl) intramuscularly injection and kept as a control. The second, third, and fourth groups were treated with oxytocin (OX) at a level of 50 I.U., prostaglandin F₂ alpha (PG) at a level of 500μgand methargin (MT) at a level of 20 mg, with 10 ml of saline solution, intramuscularly injection, respectively. The results showed that, cows administrated with OX, PG or MT recorded decrease (P<0.05) in the period from parturition to complete fetal membranes drop and uterine involution, ovarian structure, first estrus postpartum, days open and service period as well as number of services per conception and calving interval, and increase (P<0.05) the heat period length as compared to in the untreated cows, moreover cows that had received PG or MT had better values than cows that had received OX. Also, OX, PG and MT treatments increased (P<0.05) the actual milk yield compared with untreated. Values of total leukocytic count, immunoglobulins IgG and IgM, total protein and albumin and thyroid hormones T₃ and T₄ as well as glucose were increased (P<0.05) in all treated groups, while values of cortisol were decreased  (P<0.05) as compared to in the untreated group, moreover the best values were recorded with cows that were treated with PG or MT compared with cows that were administrated with OX. The highest percentages of the incidence of postpartum reproductive disorders were recorded for untreated cows, which can be decreased by administration of cows with OX, or avoided by PG or MT treatments within ½ hour postcalving. In conclusion, it can be recommended to administer lactating Friesian cows with dystocia with prostaglandin F₂ alpha at a level of 500 μg, or methergin at a level of 20 mg, with 10 ml of saline solution (0.9% NaCl) intramuscularly injection, respectively, within ½ hour after expulsion of the fetus to avoid retention of fetal membranes, postpartum complications and improve subsequent reproductive performance and blood constituents as well as milk yield and its economic efficiency under the Egyptian conditions.