Background: Preterm birth is a baby born alive less than 37 weeks calculated from the first day of the last menstrual period. Babies born prematurely have a higher risk of death, disease, disability and growth problems compared to normal infants (Zhang et al., 2012). Prematurity is a serious case of pregnancy that can be caused by anemia (Rukiyah et al, 2010). The danger of anemia in second trimester and third trimester can cause premature parturition, bleeding ante partum and death (Mansjoer A. et al., 2008). The general objective of this study was to determine the relationship of anemia in second trimester and third trimester pregnant women to the incidence of post partum hemorrhage in Tegalrejo Health Center Yogyakarta. Method: A non experimental research with case control design using medical record secondary data. This research has 60 samples were those that met the inclusion criteria and regardless of exclusion criteria that did control or gave birth at the Tegalrejo health center in Yogyakarta. Chi Square were used for the statistic test. Results: The results of bivariate analysis showed that anemia in pregnant women in second trimester had a significant relationship with the incidence of preterm birth p = 0.005 ; OR = 4.644 and 95% CI (1,562-13,812). While for anemia in third trimester pregnant women do not have a significant relationship with the incidence of premature birth p = 0.342 ; OR = 0.604 ; 95% CI (0,213-1,712). Conclusion: There is a significant relationship between anemia in pregnant women in second trimester with the incidence of premature babies. There was no significant relationship between anemia in pregnant women in the third trimester with the incidence of premature babies.