Background:Alpha-fetoprotein (AFP) is the major serum protein in the embryonic stage and in the early fetal stage.This study assessed association between second trimester maternal serum alpha fetoprotein in 14-22 weeks and adverse pregnancy outcome. Materials & Methods: 152 pregnancies were included in this study. Weight of the fetus was estimated by the Honarvar 2 equation and compared with real weight. The MSAFP levels are reported in ng/cc. Results: Age group 18-22 years had 45, 23-27 years had 60 and 28-32 years had 47 patients. The difference was non- significant (P> 0.05). The mean MSAFP in preeclmpasia was 76.1, in without pre-eclmpasia was 41.3, in preterm laborwas 55.2, in without preterm labor was 41.0, in PROM was 42.7 and in without PROM was 43.8. The difference was significant (P< 0.05). MSAFP level in oligohydramnious was 78.2, in without oligohydramnious was 40.3, in stillbirth was 36.5, in without stillbirth was 45.2, in miscarriage was 40.7 and in without miscarriage was 43.1. The difference was significant (P< 0.05). Conclusion: Pregnancies with an elevated MSAFP level are associated with adverse obstetric outcomes.