Meroplankton was studied at the Piraquê-açú River Estuary, city of Aracruz, State of Espírito Santo, with the aim to understand their temporal and spatial distribution in the environment. Samples were collected monthly (between May and December 2003) in four sampling locations distributed along the estuary, using a conical plankton net with a 50cm mouth opening and 200 micron mesh size. The samples were obtained using the net of the plankton. Temperature and salinity were measured in situ. Temperature showed higher variation between the months and salinity between the locations. The main taxonomic groups found were Cirripedia, Decapoda, Stomatopoda, Gastropoda, Bivalvia, Polychaeta, Echinodermata and Bryozoa. The most abundant groups were represented by Brachyura (mainly Uca burgersi, Eurytium limosum, Pachygrapsus transversus, Metasesarma rubripes and Sesarma rectum), Paguridae (Pagurus genus) and Diogenidae, Caridea (Alpheidae family), Cirripedia and Gastropoda. For the majority of the taxa there was significant differences between months, but only Cirripedia, Ophiuroidea and Echinoidea showed significant differences between sampling locations. The taxa found were grouped according to their abundance variation in the different months, what may reflect different life cycle strategies among species.