Objective: To determine the level of development of critical thinking of the students of the Educational Institutions of primary education in Chimbote, Peru. Materials and methods: A descriptive study was conducted in Chimbote, 2016. Critical thinking was evaluated in 250 boys and girls who belong to the sixth grade of primary education in 2016. A questionnaire of 30 questions aimed at addressing the dialogic and substantive dimensions was applied; each question included five (5) response options on the Likert scale (1 = total disagreement up to 5 = total agreement). These variables were recategorized by scaling by percentiles classified into three categories: (a) high, between 150-100 points; (b) medium, between 99-50; and (c) low, between 49-0 points. A descriptive analysis of the critical thinking variable was carried out according to its substantive and dialogic dimensions through tables with their relative and absolute frequencies. Results: here is a negative tendency in developing critical thinking, which comprises the substantive and dialogical dimensions, being the lowest level the one that obtained the highest percentage of 54%, compared to the high level of 4.4%. Conclusion: There is a deficit of critical thinking in students and in their substantive and dialogical dimensions.