Abstract. In the Atlantic rain forest (Mata Atlântica) of Northeastern Brazil the seasonality of termite swarming was studied by light trap captures. Swarming started in November and ended in July, with a high incidence at the beginning of the rain season, March through May. Alates of twenty four morpho-species of the families Kalotermitidae, Rhinotermitidae and Termitidae were sampled. The latter were the most abundant group. Sex ratio was approximately 1:1. The influence of external factors on the monthly capture rates was analysed by multiple regression, resulting in air temperature and rain fall as the main determinants. The periods of swarming now known for termite populations in different regions of Brazil are discussed under aspects of climate and habitat characters.