Mayengue PI, Batsimba DK, Niama RF, et al. - The variation of malaria cases, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year in Brazzaville were investigated. From May 2015 to May 2016, enrollment of a total of 416, 259 and 131 patients with suspected malaria was done at the Centre de Santé Intégré (CSI)«Maman Mboualé», Hôpital de Mfilou and the Laboratoire National de Santé Publique, respectively. Findings suggest variation in malaria transmission between the north and south parts of Brazzaville. Researchers observed a higher proportion of malaria cases and geometric mean parasite density at the CSI «Maman Mboualé» compared with over sites. However, there was higher multiplicity of infection at the Hôpital de Mfilou. At the Laboratoire National de Santé Publique, there appeared no influence of different seasons on malaria cases and the multiplicity of infection. However, the mean parasite density was varied statistically significantly. At the end of the main rainy season either the beginning of the main dry season, they noted higher proportions of malaria cases at the Hôpital de Mfilou and the CSI «Maman Mboualé»; while they observed lowest proportions in September and January and in September and March respectively. Mean parasite densities were higher at the end of rainy seasons with persistence at the start of dry seasons. The mean parasite densities were lowest during dry seasons, with persistence at the start of rainy seasons. On the basis of these findings, they suggest performing both meteorological and entomological studies to update the season’s periods as well as malaria transmission intensity in Brazzaville.