This study aimed to analyze the fungal contamination of air-conditioning filters waste (n=20) as an indicator of Quality Air Indoor from different car models, that were collected from 10 exchange stations located in the South, North, West, Downtown and East, of the city of S??o Paulo in S??o Paulo State, Brazil, during the period from August 2018 to December 2018. A non-selective fungal agar was used, as a commercially prepared media. Sampling consisted of filters particles (33 fragments of 10 ?? 10-mm size) were plated onto solidified agar in Petri dishes in triplicate. The samples were incubated for seven days at 25 ??C and were stored in a standard Biochemical Oxygen Demand (BOD) incubator, for growth of fungal cultures. After incubation, the fungal culture in the plates was evaluated, and the total counting of infected fragments was expressed as a percentage. The molds were examined by Lactophenol blue solution staining for microscopy. All samples were contaminated with various fungal genera, including Aspergillus, Alternaria, Cladosporium, and Penicillium. The study also aimed to evaluate the fungal enumeration in the samples that were irradiated with a dose of 10 kGy to fungal decontamination of air-conditioning filters waste. Of total samples, 50% were completed decontaminated, but yeasts, Cladosporium spp., Penicillium spp., Aspergillus niger demonstrated radioresistance at the dose of 10 kGy.