Objectives: Determine the relationship of socioeconomic factors and nutrition with growth and psychomotor development in children of the I.E. Initial Victoria Barcia Boniffatti, Iquitos, 2023. Methods: Observational study and cross-sectional design, which adopts a prospective perspective in planning data collection. Results: Maternal age showed a significant relationship with off-target psychomotor development, with an aOR of 0.906 (95% CI: 0.855–0.959; p = 0.001). The NutriSTEP variable, which indicates nutritional risk, was associated with off-target psychomotor development, although the association did not reach statistical significance (aOR: 0.939; 95% CI: 0.868–1.017; p = 0.078). Childhood growth is significantly associated with inadequate growth and off-target psychomotor development (p = 0.049). Children with inadequate growth were 1.9 times more likely (95% CI: 1.003–4.008)...