Genetic-association is a prominent word in the biomedical databases appearing in more than one million of publications. This keyword is one of the most used to find phenotypegenotype associations, identifying risk variants that could be used as biomarkers in complex diseases. Nonetheless, this word does not necessarily imply a real association, given that the human populations, as other ones, are dynamic and consequently, an important rate of statistical errors is generated. This situation is not only reflected in the classical case-control genetic association studies. Certainly, the genome-wide association studies, as well as the whole exome sequence, are susceptible of false associations. Latino/Hispanic and African- American populations present a complex genetic architecture due to the disparities in the ancestral background of populations from which they emerged. Ancestry informative markers, Bayesian inferences of a number of subpopulations, hierarchical clustering, and ancestry matching are indispensable tools to reduce the bias caused by the population heterogeneity and the inflated findings. Herein, is a short commentary where a general overview is presented about population genetic parameters and the role of ancestry to identify risk loci and its implications for medical practice. Also, the hint of the consequences of the depreciation of these arguments was done evidencing its consequences.