Background: People with a previous diagnosis of non-communicable diseases (NCDs) develop serious forms of COVID-19 or die. Mexico is the sixth country with the highest mortality rate by COVID-19 with high mortality in younger adults.Objectives: To describe the association between NCDs and Case Fatality Rate (CFR) due to COVID-19 and identify related factors. Methods: We studied all Mexican adults infected with COVID-19 from February 1st to July 31st, 2020. The data set is available for free on the Ministry of Health’s webpage. We analyzed previous diagnosis of NCDs, other preexisting diseases, indicators of severity, and the institution treating the patient. We estimated CFR and analyzed it by the number of NCDs, specific diseases, and combinations of NCDs. Relative risk was estimated using Poisson models and probability of death estimates with Logistic models.Results: We analyzed 406,966 COVID-19 positive adults. The general CFR was 11.2%, while for men it was 13.7% and for women 8.4%. CFR is positively associated with age and number of NCDs (trend test p<0.001). The combination of type 2 diabetes+chronic kidney failure has the highest CFR (44.0%). The number of comorbidities increase the CFR in younger adults, in which the relative risk from 0 to 3 or more NCDs was 30.2 in women and 11.8 in men. We observed great heterogeneity in the CFR by institution, from 4.6% in private institutions to 18.9% in public institutions.Conclusion: The number of NCDs increases CFR and explains the mortality in younger adults. Our findings are consistent with the scientific literature and contribute to the understanding of these associations.