A migration of P. flavescens (Fabr.) was observed on the coast of Santa Catarina, Brazil, in February, 1970. The passage took place during the morning hours, with a maximum between 8 and 9 a.m. Flight intensity decreased steadily within a week. A total of approximately half a million dragonflies involved in the migration was calculated. The start of the migration was not observed and the causes of the phenomenon are unknown.