the standard plaque reduction neutralization technique has been performed in BHK-21 cells for more than 20 years in Cuba to determine the neutralizing antibodies to dengue. At the end of 2007, the WHO implemented a program to harmonize this technique at all the laboratories worldwide.the present study was aimed at standardizing the plaque-reduction neutralization technique in Vero cells from the Cultural Lab of"Pedro Kouri" Tropical Medicine Institute.viral strains suggested by Who, strains from the Strain Bank of Arbovirus Laboratory, as well as the panel of human sera from dengue-suspected patients after 5 days of the symptoms.it was proved that suspension- cultured Vero cells allow higher plaque capacity and quality. Similar results were reached using Arbovirus Bank strains and WHO reference strains.it was possible to standardize the plaque-reduction neutralization in Vero cells, with results similar to those of BHK-21 but in longer length of time. Standardization of this technique will allow comparing the outcome of neutralization in the epidemiological studies and vaccine research with those of other laboratories worldwide.