This is the first record of Ceratium furcoides in the Nova Avanhandava reservoir, São Paulo, whose samples were collected in three stations (S1, S2, S3) in March and October of the years 2015 and 2016. Physico-chemical analyzes of the water were performed. The reservoir was classified, according to the TSI, as mesotrophic. The first record of the species occurred in October 2015 at S3 and, the following year, the dispersion for the other stations was verified. The highest density of the species (28 org mL-1) was recorded in October 2016. Similar values were documented in Furnas (MG) and Ilha Solteira (SP). The low density values of C. furcoides and the presence of phytoplankton groups with higher densities (Cyanobacteria and Cryptophyceae) suggest that the colonization of the species is at an early stage. Thus, studies about dispersion, dynamics, and interaction of C. furcoides with phytoplankton and the potential impacts on aquatic communities are essential to understand the responses of this species to environmental conditions.