Objective: to classify renal function in patients with diabetes mellitus type 2 (dm2) and hypertension through the determination of glomerular filtration rate and to identify the frequency of the use of the mdrd and ckd-epi formula. Methods: cross-sectional and descriptive study. Clinical records of diabetic and hypertensive patients from a Family Medicine Unit (fmu) in Ciudad Mante, Tamaulipas, Mexico were reviewed. To determine the sample the finite population formula was used. Sociodemographic and laboratory results were gathered through the review of the records and the glomerular filtration rate was calculated. Data was reviewed using descriptive statistics. Results: 150 records were analyzed. 30 (20%) patients had diabetes, 63 (45%) hypertension, and 57 (38%) suffered from both diseases. At the time of the study 10 (7.5%) patients were at a stratification renal stage. After calculating the glomerular filtration rate. According to the Kidney Disease Outcomes Quality Initiative (kdoki) classification, it was determined that 84 (56%) were in stage 1, 45 (30%) in stage 2, and 21 (14%) in the advanced stages of the disease. Conclusions: the referral results show that there is a misdiagnosis of renal disease. Resources are not adequately used to classify patients with dm1 and hypertension presenting a renal disease.