The occurrence of aflatoxins B1 (AFB1), B2 (AFB2 ), G1 (AFG1 ) and G2 (AFG2 ), ochratoxin A (OA) and zearalenone (ZEA) was evaluated in 121 maize-based food samples collected in the commerce of Maringá City, Paraná State, Brazil. The study was carried out between January 2002 and February 2003. Thin-layer chromatographic method was used to determine the mycotoxins. The recovery averages were 106.6%, 109.4%, 106.6%, 109.4%, 101.8% and 101.7% to AFB 1 , AFB 2 , AFG 1 , AFG 2 , OA and ZEA, respectively. Three samples (2.5%) were positive to AFB1 (8 to 59 μg/kg), two (1.7%) to AFB2 (2.4 μg/kg), one (0.8%) to OA (64 μg/kg) and one (0.8%) to ZEA (448 μg/kg). The greater frequency of positive samples and also the highest concentration of AFB1 were found in popcorn samples (8.3%, 59 μg/kg). The data showed a low frequency of mycotoxins in products based on maize traded in Maringá, but the Probable Average Daily Intake (PDI) of AFB1 in them was high. Therefore, it is necessary to accomplish an active vigilance of these mycotoxins in such food products in order to provide safety to Brazilian people health.