Objective: To determine the diagnosis of Chronic Renal Insufficiency, by Cockcroft formula, in type II diabetic patients aged 40 to 80 years old from the community of Santa Cruz, Hecelchak?n during the period from August 20017 to July 20018. Materials and methods: This is a prospective, cross-sectional, descriptive and observational study in which the diagnosis of renal failure in any of its 5 stages will be investigated. Patients were asked for laboratory tests of plasma creatinine, weight and age, to later calculate the creatinine clearance using the Cockcroft and Gault formula and classify the stage of renal failure in which each patient is to formulate plans of practice of according to your state. Results:We found 10 cases with chronic kidney disease in stage 1, 3 men and 7 women, in stage 2 8 patients were found, 2 men and 6 women, and 5 patients with stage 3, all of them female. Conclusions: In the community of Santa Cruz, Hecelchak?n, there is a prevalence of 3.9% in diabetes mellitus, 42 people who come monthly from a total population of 1,060 according to the November 2017 population census.