Data of Holstein dairy cows in a private farm (TEC-DAP) in Al-Fayum Governorate comprising 5815 calving events (80 for twins and 5735 for singles) in the period from January 1997 to April 2008 were used to determine if there was any significant difference between twin and single calving cows in gestation length, reproductive performance, incidence of dystocia, perinatal calf survival and mortality rates and culling rate. Cows giving twins had shorter (p < 0.0001) gestation and more (p < 0.005) days to first heat, first service and days open than cows giving singles. Incidence of dystocia was higher in cows with twins (22.5%) than those with singletons (7.22%). Survival rate of singles was 12.9% greater than that of twins at birth, whereas perinatal mortality rate was 16.25 % (9.37% stillborn & 6.88% dead after birth) for twins and 3.33% (2.06% stillborn & 1.27% dead after birth) for singles. Culling rate was greater in cows producing twins (61.53%) than those with singles (30.73%). Twinning in cattle shortens the length of gestation, impairs subsequent reproductive performance by prolonging postpartum breeding intervals, increases the incidence of dystocia and perinatal calf mortality and increases number of cows to be culled during subsequent lactation. Thus, twinning in dairy cattle is undesirable due to its detrimental effect on cow fertility and health and calf survival. However, these adverse effects can be minimized by preparturient diagnosis of twin pregnancy and timely administration of obstetrical assistance which aids in management of dystocia to facilitate delivery of twin calves and to increase their neonatal survival.