The main objective of the research was to determine the water quality of the Estero Salado de Guayaquil by assessing the measurements of pH, dissolved oxygen, and chlorophyll in 7 stations from March to December  2020. The samples were analyzed in the laboratory according to the methodology used for each parameter. The ANOVA test of a factor with a significance level of 0.05 was used and the results showed that there are no significant differences in pH and chlorophyll a; however, 12 significant differences were found in the dissolved oxygen. The pH means to comply with the provisions of the Ecuadorian environmental regulations, and the average dissolved oxygen value is below the required. For Chlorophyll A, it helped to determine that the estuary presents an oligotrophic state. Results showed that the waters of the Salt Estuary of the study area are not suitable for the development of aquatic organisms.