(EBM) as one method to reduce postnatal transmission of human immunodeficiency virus (HIV) in developing countries. Flash-heat is a simple heat treatment method shown to inactivate cell-free HIV. Objective—To determine the effect of flash-heat on vitamin content of milk. Methods—Fresh EBM was collected from 50 HIV+ mothers in Durban, South Africa. Mothers washed their hands and then manually expressed 75–150 mL EBM into sterile jars. Milk was aliquoted to unheated controls or flash-heat (50 mL EBM in a glass jar heated in a 450-mL water jacket in an aluminum pan until water boiled, then EBM removed) simulating field conditions with an open flame. Samples were stored at −70°C and then analyzed for the effect of flash-heat on vitamins [A, ascorbic acid, riboflavin (B2), pyridoxal-5-phosphate (B6), folate, and B12]. Results—Vitamin A was not significantly affected by flash-heat and vitamins B12 and C and folate increased significantly. Vitamins B2 and B6 were decreased to 59% (95% confidence interval 44 to 81) and 96% (95% confidence interval 92 to 99), respectively, of that found in unheated milk. Conclusions—The percentage remaining after flash-heat suggests that most vitamin concentrations are retained after heating. Flash-heat may be a practical and nutritious infant feeding method for mothers in developing countries.