An analysis of the temporal and spatial variation of the mesozooplankton with respect to its abundance and composition was carried out in the eastern zone of the Gulf of Cariaco, Venezuela. Monthly samples were collected (June 2009 to May 2010) from nine stations distributed in three zones. A standard plankton net of 333 μm was used. Temperature, salinity, phytoplankton biomass and nutrient concentration were measured. The temperature varied from 22.50 - 28.56 ° C, salinity from 32.54 - 40.21 ups and the phytoplankton biomass between 0.01-26.49 mg.Clor. a.m-3. The concentration of nutrients was high. Salinity, silicate and phosphate were the only variables that had seasonal differences. The importance of these two nutrients in biogeochemical processes in the Gulf was corroborated by the ACC. Abundance varied between 7 - 4431 ind.m-3, and had temporal and spatial differences, with the highest concentrations during the rainy season, in zones 1 and 3. This increase was related to the contributions of rivers and wastewater from the surrounding villages, causing a mixing zone. 46 species of copepods were identified. Acartia tonsa was the most abundant and frequent. The rainy period was the main factor responsible for the variations in the hydrology of the Gulf, and had a direct effect on the abundance, diversity and distribution of mesozooplankton.