In a survey of the mycoflora and mycotoxins in foods and feeds, 66 samples of mixed poultry feeds and some component raw materials were investigated. Fungal counts ranged from < 10(2) to 1.3 x 10(6) CFU/g. Fusarium spp. counts ranged from 10(2) to 1.0 x 10(6) CFU/g. The fusarium spp. strains isolated were screened for their potential to produce fumonisin B1 (FB1) and fumonisin B2 (FB2) in maize cultures. Samples and maize cultures were analysed for FB1 and FB2 using TLC and fluorescamine-derivative HPLC. No fumonisins were detected in the samples (< 6 ppm). Fusarium moniliforme was isolated in 59.1% of samples, and 97.4% of the strains produced FB1 and 79.4% of strains produced FB2 in maize cultures. Some isolates produced higher FB1 and FB2 levels than the reference strain F. moniliforme MRC 826.