Aflatoxins are carcinogenic and may affect linear growth. Prior cross-sectional data from Ghana have shown that aflatoxin levels are ~ 20% higher among HIV-infected than HIV-uninfected post-partum women. It is not known if HIV-infected pregnant women have elevated serum aflatoxin levels during pregnancy, or if aflatoxin levels change during the perinatal period. We therefore studied these relationships among a cohort of 246 women recruited in Gulu, Uganda, and followed through pregnancy and early infant life. All HIV-positive women received HIV antiretroviral therapy for free from the government clinic.