Objective: To find incidence of congenital thrombophilia in unexplained infertility  versus fertile female population with intend to determine if thrombophilia is a possible  cause and which type of thrombophilia is more prevalent in unexplained infertility. Methods: Study group (Group A) comprised of 40 infertile patients of age between 20- 40 years in whom no cause of infertility was identified. The control group comprised of 40  healthy women with proven fertility, matched for age, with no history of thrombo-embolic  events. Both the groups were tested for inherited thrombophilia included Protein C, Protein  S, Anti-thrombin III, Activated Protein C Resistance, Homocysteine, factor V Leiden (PCR),  Prothrombin G20210 G gene and M THFR (677c/T)gene mutation. Results: Overall 14 (35%) subjects in the unexplained infertility group, and  5 (12.5%) in the control group were detected with positive thrombophilic factor  (p value-0.023). Out of 14 positive cases, 7/14(50%) had more than one factor    (35% had 2 and 15% had 3 factors)thus 23 thrombophilia factors in 14 women in group 1  in comparision of onlt 7 in 5 in (2 with 2 factors)group2 (p=0.005). Out of 23, Protein S  (10%) and Antithrombin III (10%) had the highest frequency followed by Homocysteine  (7.5%), Protein C (7.5%), MTHFR gene mutation (7.5%), prothrombin 20210 (5%), Factor  V Leiden (5%) and APCR (5%)in group1 Out of the 7 thrombophilia factors in controls,  Factor V Leiden mutation and APCR had the highest frequency (5%) followed by Protein  S, Protein C, and Homocysteine (2.5%). APCR  and Factor V leiden were similar in both groups  whereas Hyperhomocysteinaemia combined with  MTHFR gene mutation was more in unexplained  infertility andprothrombin gene was found only in  unexplained infertility Conclusion: There is significant association  of thrombophilia with unexplained infertility  Hyperhomocystinaemia combined with MTHFR  gene mutation and APCR with prothrombin gene  mutation are more likely to be associated with  unexplained infertility. Thrombophilia evaluation  may be included along with other tests in evaluation  of unexplained infertility.