Milk is among the most important foods used in the daily diet of children and maybe a suitable option for fortification with minerals such as iron that help reduce iron deficiencies and anemia in children. The objective of the present investigation is to fortify with heme iron from pig blood powder, and pasteurized milk with chocolate flavor and to study its sensory acceptability in a group of children aged 3-5 years. The study variables in milk preparation were iron concentration and sugar content. The compound factorial design and the response optimization allowed for finding an optimal range corresponding to 25% of the recommended dose of iron for children. The formula with the highest acceptability (4.72/5) presented a concentration of 13.65 mg Fe L-1 , 693 mg L-1 vitamin C and 60 g L-1 sugar. According to the physicochemical and microbiological results, the fortified flavored milk complied with regulations and had an approximate shelf life of 5 days. These results showed an alternative for heme iron fortification of chocolate milk, whose content could contribute to the daily requirement of this mineral in children aged 3- 5 years (11 mg of iron per day for a consumption of 250 mL).