Candida dubliniensis is a recently described pathogenic species that shares many phenotypic features with Candida albicans and so may be misidentified in microbiologic laboratories. The aim of this study is to find a useful and cost-effective method suitable for screening C. dubliniensis before proceeding to further identification. We examined the colony morphology and chlamydospore production of 26 C. dubliniensis isolates and 100 C. albicans isolates on the following 5 proposed media: sesame seed agar (SSA), rapeseed agar, canary grass seed agar, millet seed agar, and linseed agar (LA). The best results were obtained with SSA and LA because all 26 C. dubliniensis isolates showed rough colonies with peripheral hyphal fringes and abundant chlamydospores after 24 to 48 h of incubation at 25 degrees C. All C. albicans isolates (100%) showed smooth colonies without hyphal fringes or chlamydospores. These 2 media consist of new and simple tools for presumptive differentiation of C. dubliniensis from C. albicans.