Hemoglobin Hammersmith is a rare unstable variant of hemoglobin with decreased oxygen affinity. We report the case of a 3-year-old Colombian girl that initially consulted due to a presumptive diagnosis of iron deficiency anemia. During the evaluation we noticed typical features of chronic hemolytic anemia such as hepatosplenomegaly, jaundice and indirect hyperbilirubinemia; with the presence of target cells and intraerythrocytic inclusions with appearance of tactoids in the peripheral blood smear. The diagnosis of hemoglobin Hammersmith was confirmed through DNA sequencing revealing a pathogenic heterozygous variant in the beta globin chain gene due to a de novo mutation.