High quality is recommended for drinking water to prevent the transportation of pathogenic bacteria. To ensure its quality, different technologies are applied, and copper-silver ionization is used to maintain the microbiological quality. However, considering that the characteristics of this source vary in different scenarios, it was proposed to evaluate the efficacy of copper-silver ionization for the disinfection of drinking water in Tumbes, Peru. For this evaluation, the physicochemical and microbiological parameters of drinking water were tested at different lengths of copper-silver ionization treatment (10, 20 and 30 minutes). Water samples were collected from 20 houses located in urban areas of Tumbes city where Cu-Ag ionizers (Necon GmbH) were installed. The application of Cu-Ag ionization reduced the microbiological load in the water samples, keeping them below the Peruvian permissible limits (mesophilic bacteria < 500 CFU/100 mL and coliforms < 0 CFU/100 mL). However, in samples with a high microbial load and high electrical conductivity, the microbial load was not completely diminished. Cu-Ag ionization considerably improved the microbiological quality of the water, but some physical parameters, such as pH and electrical conductivity, must be taken into account to further improve the results.