Introduction & Objective: Vaginal bleeding is a common complication during pregnancy, which is observed in about one fourth of pregnancies, and in half of the cases it can lead to abortion. In other cases the rate of adverse pregnancy outcomes, including perinatal mortality and morbidity, low birth weight and preterm delivery will be increased. The aim of this study was to find the association between vaginal bleeding in the first half of pregnancy with adverse pregnancy outcomes. Materials & Methods: This prospective study was done in 2010 on 200 pregnant women with singleton pregnancy over 20 weeks in two similar groups of 100 patients with vaginal bleeding in first half of pregnancy (cases) and without bleeding (control group). The two groups were matched in terms of demographic characteristics such as age, occupation, level of education and parity were matched. Maternal and neonatal outcomes (preterm labor, intrauterine death, prenatal mortality, placental complications, apgar of first and fifth minutes, and obvious congenital anomalies) of pregnancies of mothers’ records were reviewed. For reporting the results, SPSS 16 and chi-square technique was used. Results: In this study, all adverse maternal and neonatal results were higher in the group bleeding than in the group without bleeding but this higher risk was statistically significant for cesarean (P=0.05) prenatal mortality (P=0.01), LBW (P=0.04) and preterm labor (P=0.001) with gestational bleeding. So,for the case of cesarean rate 1.8 times, for Low birth weight (W