Aim: The aim of the present preliminary study was to determine sugar concentration in infant follow-on formulas most widely consumed in Peru. Materials and methods: In this descriptive and observational study, the sample was represented by five brands of infant follow-on formulas most consumed in Peru (A, Similac 2; B, Enfamil 2®; C, NAN 2®; D, Baby Lac Pro 2®; and E, Lacti Kids Premium 2®); with two samples of each, collected at two different locations in the Peruvian capital. Subsequently, the concentration of total and individual sugars (lactose, sucrose, glucose, fructose, and maltose) was determined using the high-performance liquid chromatography (HPLC) method in a specialized laboratory. For the comparison of means, Welch’s robust analysis of variance (ANOVA) test for equality of means and Tukey’s post hoc test were used. The significance level was p < 0.05. Results: The t...