Recurrent Pregnancy Loss (RPL) is recognized as the loss of a clinical pregnancy before 20 completed weeks of gestational age. This was a descriptive-analytical case-control study conducted at the research laboratory of the national centre of neurological sciences (NCNS), Khartoum, Sudan. The study aimed to detect factor XIII gene polymorphisms among Sudanese women with recurrent spontaneous abortion. Women with more than three recurrent abortions were included in this study as cases and those healthy women with no history of abortion at reproductive age were included as controls. From each participant 3 ml of venous blood was gathered in sterile containers. The factor XIII gene was amplified using conventional PCR. All cases were positive 44 (100%) while 30 (60%) were positivein the control group and 20 (40%) were negative. There was a significant difference between the PCR result of the cases and that of controls (P= 0.000). A high frequency of factor XIII gene polymorphisms was found in women with recurrent spontaneous abortion than those healthy women at reproductive age without abortion.