Diabetes mellitus (DM), diabetic nephropathy (DN) and chronic kidney disease (CKD) are prevalent diseases in our region, South America. The levels of hemoglobin A1c (HbA1c) have been related to the development and progression of the DN. Two decades ago there was great variability in the results; the leading countries in scientific research then organized programs of HbA1c standardization, which improved the quality and reliability of the findings. The objectives of this study were to describe the problem of DM, DN and CKD in South America and to analyze HbA1c methodologically in this context. Thus, the impact of these diseases in our region was reviewed, contemplating basic aspects of HbA1c and some situations that produce interferences such as carbamylation of hemoglobin, the post-translational modification associated with uremia. We also focused on statistical techniques universally used for the evaluation of assays such as linearity, concordance and precision. Additionally, we included an analysis of the existing methods and the prices of each HbA1c determination in ten countries in South America. To prevent, diagnose and treat DM, DN and CKD, it is essential to have state-of-theart tools available to all people. In our region, access to trials, equipment and laboratories within HbA1c standardization programs, internationally accepted, is a pending task. Millions of individuals from the present and future generations of South America will suffer from DM, DN and CKD, so we need to take the voice of science to these people through the daily "doing".