Four yeast strains (TM1-01(T), TM1-07, TM3-47 and TM3-49) were isolated by membrane filtration from estuarine water collected from a mangrove forest in Phang-Nga province, southern Thailand. Analysis of the D1/D2 domains of the large-subunit rDNA sequence revealed that the sequences of the four strains were identical. The closest recognized species in terms of pairwise sequence similarity was Pichia deserticola, but the level of nucleotide substitution (4.8 %) was sufficient to justify the description of a separate species. Phylogenetic analysis demonstrated that the four strains occupy a basal position with respect to Pichia membranifaciens and close relatives. The four strains showed identical phenotypic characteristics, including proliferation by multilateral budding, absence of ascospores, arthrospores and ballistospores and negative reactions for Diazonium blue B and urease. The major ubiquinone was Q-7. On the basis of the above findings, these four strains were assigned to a single novel species of the genus Candida, for which the name Candida thaimueangensis sp. nov. is proposed. The type strain is TM1-01(T) (=CBS 10360(T)=NBRC 101967(T)=BCC 21229(T)).