(Oomycota from “Parque Estadual da Ilha do Cardoso” (PEIC): first records for São Paulo State and Brazil). We studied the oomycetes diversity from soil and freshwater samples collected quarterly from August 2012 to June 2013 at “Parque Estadual da Ilha do Cardoso” (PEIC), São Paulo State, Brazil. Among the species identified by morphological and/or molecular (complete ITS rDNA region) analysis, four are recorded for the first time for Brazil: Araiospora streptandra var. streptandra Kevorkian, Achlya primoachlya (Coker & Couch) TW Johnson and RL Seym., Aplanopsis terrestris Höhnk and Saprolegnia aenigmatica Sandoval-Sierra & Diéguez-Uribeondo and three for São Paulo State: Achlya crenulata Ziegler, Brevilegnia longicaulis TW Johnson and Saprolegnia truncata RL Seym. All species are described, commented and illustrated herein. The specimens were deposited in the culture collection of the “Instituto de Botânica (CCIBt)” and/or in the Herbarium SP. The ITS rDNA sequences obtained were deposited in the GenBank.