Objective: Repeat pregnancy loss (RPL) must be a painful and frustrated situation to couple. Advanced maternal age is related with miscarriages, which is predisposed to a greater risk of fetal aneuploidy. It has been proposed biological ovarian age is more important than chronologic age. The aim of this study was to evaluate whether antimullerian hormone was associated with pregnancy loss in unexplained RPL women. Methods: RPL patients were consecutively registered in this study for 3 years. Unexplained RPL was defined after excluding the genetic, anatomic, endocrinological cause and antiphospholipid antibody syndrome. Finally, 152 women were enrolled as unexplained RPL. Serum AMH levels were defined as low (< 1.0ng/ml), normal (1.0-3.5ng/ml) and high ( >3.5ng/ml). To compare other etiological causes, NK cell proportion, protein C activity, protein S activity, antithrombin III, homocystein and PAI-1 were evaluated. Pregnancy rate and miscarriage rate were compared depends on the AMH levels. Results: Mean age of enrolled women was 34.11±4.51 years-old, mean parity was 0.18±0.40, and mean number of miscarriage was 2.51±1.01. AMH level was significantly correlated with age (r=-0.51, p<0.01) However, AMH or maternal age was not correlated with ongoing pregnancy or miscarriage of subsequent pregnancy. Depending on AMH levels, mean value of NK cell proportion, protein C activity, protein S activity, antithrombin III, homocystein and PAI-1 were not different. Pregnancy rate in normal AMH group was 34/54 (63.0%), higher than 44/74 (48.7%) of high AMH group, 11/24 (45.8%) of low AMH group, statistically insignificant. Miscarriage rates of each group were not statistically different (36.4% in low AMH group, 23.5% in normal AMH group, 25.0% in high AMH group). For subgroup analysis with patients under 35 years-old, pregnancy rate or miscarriage rated was not different either. Conclusion: AMH values were not associated with subsequent pregnancy loss in women with unexplained RPL. Further larger studies are required.