Background: The World Health organization defines postpartum anemia as hemoglobin <11g/dl at 1 week postpartum and <12g/dl at 8 weeks postpartum. Postpartum anemia can also be defined as less than 11.8 g/dl for women aged 12–15 years and less than 12g/dl for women at least age 15 years. In Uganda, 23% of women age 15-49 are anemic, with 18 percent having mild anemia, 5 percent having moderate anemia, and less than 1 percent having severe anemia. Objective: To determine the incidence and factors associated with the new cases of post natal anemia in Mbarara Regional Referral Hospital. Methods: A prospective cohort study of 271 postpartum mothers without anemia enrolled on discharge after delivery. Participants were followed up to determine development of anemia at 10 weeks postpartum and associated factors on the subsequent postnatal visits. Incidence of postpartum anemia in MRRH was 29.9%, 95% CI (24 - 35). Helminthes infestations AOR95%CI; 12.88(5.25- 31.64, P<0.000), malaria infections AOR95%CI 4.74(1.50-14.94, P=0.008), poor hematinic adherence AOR95%CI, 6.81(3.17-14.62, P<0.000), high parity AOR95%CI, 2.48(1.11- 5.54, P=0.026), and husband unemployment AOR 3.92(1.14 – 13.39, P=0.030) were found to be statistically associated with post-partum anemia. Conclusion: The incidence of postpartum anemia in Mbarara Regional Referral Hospital is very high. Hematinics non adherence, husband unemployment, increased parity; malaria infection and helminthes infestation were found to be associated with post-partum anemia at MRRH
