The purpose of this study was to isolate fungi from the quarter milk of cow udders from several dairy herds and to identify the different genera and species involved in mastitis. A total of 2078 milk samples from normal, clinical and subclinical mastitis quarters from 22 dairy herds of 16 districts in the State of São Paulo, Brazil was utilized in this survey. Two hundred and fifty one (12.07%) fungi were isolated from the samples. Two hundred and eight of these (82.86%) were yeasts and 30 (11.95%) were moulds. The fungi were isolated in pure culture (24.77%) or in cultures mixed with bacteria (72.22%). The yeasts isolated were: Cryptococcus spp. (71 strains), Rhodotorula spp. (40), Candida spp. (68), Trichosporon cutaneum (21), Aureobasidium pullulans (7), and Pichia ohmeri (1). Moulds classified in following genera were also isolated: Aspergillus (3), Penicillium (3), Alternaria (3), Phoma (3), Epicoccum (2), and Geotrichum (16).