In this study 672 pregnant Sudanese women were involved in order to determine the reference values of human chorionic gonadotropin (hCG) and alpha feto protein (AFP). Blood samples were collected from different maternity centers in Khartoum and Omdurman maternity. Sensitive immunoradiomeric assay (IRMA), method was used for measuring HCG and AFP in maternal serum. The data collected reveals that, the behavior of both AFP and hCG resemble that of the international one, where the peak concentrations of hCG are reached at 7-9 weeks of pregnancy then decrease, then staying relatively constant during the second trimester and increasing slightly towards term. The maternal serum concentration of AFP increases during pregnancy, reaching its peak during the last trimester. The concentration of AFP and hCG in maternal serum with relative couples was also compared to that of irrelative couples. Relative couples showed significant increase in maternal AFP level in the 1 st and 3rd trimesters (p= 0.001& 0.000) respectively. The hCG concentration in both groups was not significantly different throughout the pregnancy (p >0.15). It is recommended that each laboratory establishes its own normal values. Since Sudanese obstetrician depends previously on values from abroad, this study may help them to handle their patients depending on our own reference values.