Recurrent Pregnancy Loss (RPL) is a multifactorial condition, defined as two or more consecutive pregnancy losses. After chromosome abnormality, thrombophilia is one of the most important genetic factors that could cause RPL. Our Objective is to evaluate the prevalence of aPCR in Syrian women with RPL compared with women who had uneventful pregnancies. This case control study was conducted to evaluates the frequency of aPCR in 100 women with RPL (who have two or more pregnancy losses), compared with 100 women without adverse pregnancy outcome. The presence of aPCR in RPL group was 30% while it was 11%t in the control group. This study has shown that aPCR (regardless of FVL mutation) is significantly associated with RPL compared with controls (P<0.05). These data support the hypothesis that thrombophilia accompanied with aPCR may plays a role in the pathophysiology of primary RPL, and suggest that attention should be directed at screening women with recurrent pregnancy loss for aPCR assays.