Introduction: anemia in children can cause cognitive and motor deficits that can lead to difficulties in academic performance, physical endur-ance, affecting health and well-being Objective: to develop and validate a scale of beliefs about adherence to iron supplementation treatment in mothers of children with anemia (SBAIST) living in a high altitude region of Peru. Methods: a cross-sectional study was conducted in 192 mothers of children with anemia living in a high altitude region of Peru. The Health Belief Model (HBM) was used to develop and validate the SBAIST. Expert judgment analysis (Aiken’s V) was used for content validity and exploratory factor analysis for construct validity. Reliability was determined by internal consistency. Results: for content validity, Aiken’s V test showed concordant values for relevance (0.60 to 0.90), relevance (0.75 to 0.95), clarity (0.80 to 0.90) and total scale (0.75 to 0.92). Cronbach’s alpha values per question ranged from α = 0.70 to 0.81, and for total scale was α = 0.75. The exploratory factor analysis (EFA) reflected Kaiser-Meyer-Olkin (KMO) values of 0.733, Bartlett’s test of sphericity indicated a value of 968.680 (p < 0.001). The eigenvalues in the five dimensions reflected values from 1.05 to 4.03. The percentage of variance for factor 1 (barri-ers = 33.58 %), factor 2 (severity = 12.61 %), factor 3 (action cues = 10.78 %), factor 4 (barriers = 8.07 %), factor 5 (susceptibility = 7.63 %), and for the total scale was 74.12 %. Conclusion: HBM is a useful tool that allowed validation of the scale of beliefs about adherence to iron supplementation treatment in mothers of children with anemia living at high altitude in Peru.