Iron deficiency prevalence in infants is high. Therefore, iron supplementation has been recommended and specified as a program. This study aimed to determine the characteristics of the prescription of ferrous sulfate as a preventive therapy for iron deficiency anemia in young infants.We conducted a descriptive cross-sectional study of clinical records of young infants with eight visits per year. We analyzed a total of 287 records. The prescription characteristics included five criteria prescription indication, age at prescription, dosage, periodicity, and time. These characteristics were scored as follows 1 point when it was considered adequate and 0 when it was considered inadequate; the minimum possible score was 0, and the maximum possible score was 5 points. Statistical analysis included percentages and 95% confidence intervals (CI).The prescription pattern of ferrous sulfate as preventive therapy in infants under one year of age was indicated in 100% of the records reviewed. All five criteria were met in 18.1% of the reviewed records (95%CI 13.6-22.6). The lowest compliance corresponded to adequate dosage (29.2%; 95%CI 23.9-34.5). Age at prescription was correct in 75.9% (95%CI 70.9-80.9); duration of prescription was correct in 44.2% (95%CI 38.4-50.0), and periodicity was proper in 31.1% (95%CI 25.9-36.7) of the files reviewed.Compliance with the prescription of ferrous sulfate as a preventive measure for anemia in infants was not as expected; interventions are needed to reverse this behavior.Copyright: © 2022 Permanyer.