This article shows the capacity of the Kohonen method in the classification of similar rivers in the light of the determination of regional ecological flows in the Magdalena-Cauca basin, using the methodology of the Ecological Limits of Hydrologic Alteration (ELOHA). For this were used 174 flow stations located throughout the basin, which could be obtained in each case 73 variables for the classification pr ocess within ELOHA. Six trials were conducted with different different combinations of variables and the criterion for determining the suitability of each combination to classify the streams of the Magdalena-Cauca basin. When the different combinations were estimated with the Kohonen method, we obtained a similar number of groups to the reference number obtained by Ingfocol in 2010, which was also framed within the guidelines of ELOHA, but using other classification methods different from Kohonen. It was found that the combinations ofvariables that best were adjusted to the reference classification were the combinations with lower number of variables which were created in order to characterize in summary form the hydrograph of each analyzed flow station.