levando em conta a qualidade das sementes plantadas e a rotação de culturas é indicada para região, uma vez que o solo e as futuras sementes se encontram contaminadas com A. flavus e A. parasiticus. Palavras-chave: Aflatoxinas; Ácido ciclopiazônico; Fumonisina; Fungos. ABSTRACT GONÇALEZ, E. Fungal and mycotoxins distribution in peanut samples from sowing to harvest. 2008. 94 f. Ph. D. thesis (Microbiology) -Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, 2008.The elucidation of the contamination way of the toxigenic fungi and mycotoxins in peanuts of field conditions is very important, so as to develop effcent control strategies. These facts in association with the peanuts "in natura" and your products are used in human and animal and the high frequency of toxigenic fungi like A. flavus and F. verticillioides in Brazil and the importance of the mycotoxins study, motivated this work. Under these considerations, the present study aimed to: 1. Identify the mycoflora of the soil, air, flower, pegs, peanut kernels and hulls in the differents maturation stages and after drying; 2. Determinate the occurrence of aflatoxins B1, B2, G1 and G2, cyclopiazonic acid (CPA) and fumonisins B1 and B2 in peanut kernels and hulls in different maturation stages and after drying. The mycoflora study of the peanut kernels and hulls showed that Fusarium spp.Aspergullus flavus were the most frequent fungi isolated. A. flavus also isolated in soil and air samples. A. parasiticus was isolated in the peanut kernels only after drying. The A. flavus strains analyzed, 85.72% can be able to produce aflatoxins, 38.09% produced CPA too, 33.33% produced both toxins and 4.76% produced only CPA. All A. parasiticus strains produced aflatoxins. Aflatoxins and CPA were detected in 32%of the peanut kernel samples in concentration from 4.20 µg/kg to 198.84 µg/kg and from 260 µg/kg to 600 µg/kg, respectively. These mycotoxins were detected from pod filling stage. In the peanut hulls only aflatoxins were detected in 24% of the samples in concentration from 5.76 µg/kg to 218.52 µg/kg. This present study showed for the first time the natural co-occurrence of the aflatoxins and cyclopiazonic acid in Brazilian peanuts samples as well as the isolation of toxigenic strains of the A. flavus producer for the both toxins.Fumonisins were not detected in peanut kernels and hulls samples, but two toxigenic F. verticillioides were isolated. Good agriculture practices are indicated to region, because the soil and the future peanut kernels are with toxigenic fungi A. flavus and A. parasiticus.