This study aimed to isolate filamentous fungi from the fur of primates of the genus Callithrix kept in the Centre for Rehabilitation of Wild Animals (CRWA) at the Tietê Ecological Park, São Paulo, SP, Brazil. Samples of the fur of 19 specimens of black-tufted marmosets (Callithrix penicillata) and 6 specimens of white-tufted-ear marmosets (Callithrix jacchus) were obtained by the square carpet technique. The samples were plated on Mycosel™ agar medium (Difco™) and incubated at 25°C for 21 days. The identification of each isolated mold was based on its macroscopic and microscopic features and followed classical recommendations. The following filamentous fungi were isolated: Penicillium spp. (76%), Cladosporium spp. (60%), Acremonium spp. (44%), Scopulariopsis spp. (24%), Aspergillus spp. (16%), Chrysosporium spp. (16%), and Fusarium spp. (8%). Dermatophyte fungi were not detected. We conclude that C. penicillata and C. jacchus kept in captivity are sources of potentially pathogenic filamentous fungi that may represent a risk factor for immunocompromised individuals who may eventually establish contact with them.