Economic losses of dairy products due to spoilage by yeasts have been increasing in European companies because of the reduced use of preservatives, packaging in modified atmospheres, or new formulations that do not strictly control the growth of these organisms. This study reports the results of a survey of yeast species and populations in 145 samples of cow and buffalo dairy products collected in some regions of Southern Italy. Yeasts were isolated from 74% and 57% of cow and buffalo products, respectively. Candida inconspicua was the predominant species in unripened products from cow's milk, while C. famata was detected in medium and long-term ripened dairy products, mostly in association with other yeasts and with moulds belonging to the genus Penicillium. For dairy products produced from buffalo milk, C. inconspicua was the most important yeast frequently isolated from dairy products. Total yeast populations ranged from 5 x 10(2) to 5 x 10(5) cfu/g, indicating a good hygienic quality of the products. The isolation of C. albicans from one stracciatella sample is noteworthy, as this yeast represents a potential contamination by human. Even though yeasts are considered as environmental contaminants, the occurrence of some of them in dairy products at high levels could represent a risk for human health, in particular for immunocompromised patients.