In the present work, the occurence of aflatoxins B and G as well as a possible correlation between both were studied in 116 samples of peanut flour from 17 oil mills of the region Paulista Nova, in the State of São Paulo. The samples were obtained in four collections representing material from two crops in two different seasons: March and May in the rainy season and July and September in the dry season. From the results it was concluded that: a) the occurence of aflatoxin was generalized in that region, for all the samples were toxic; b) the toxicity level was found to be very high (figures from 0.1 to 20.0 ppm) being much higher in the rainy season-average of 5.50 ppm - against 1.76 ppm in the dry season; c) it was considered that only 10.35% of the material examined could be utilized for admixturing in feedstuffs; d) it was found a weakly positive correlation in the production of the aflatoxins B and G.