The effect of γ‐irradiation on fumonisin B1(FB1) and fumonisin B2(FB2) occurring in maize materials has been investigated together with the stability of fumonisins in γ‐irradiated maize stored at different temperatures (‐18 to +40°C) for different periods (2, 4, 13 and 26 weeks). Fifteen kGy γ‐irradiation was required to sterilize efficiently maize flour. This process caused a decrease in fumonisin content of about 20%. The stability studies showed that fumonisins are stable in γ‐irradiated maize for at least 6 months at 25°C or at least 4 weeks at 40°C. These data indicate that γ‐irradiation is an appropriate technique for obtaining sterilized maize materials to be used for intercomparison studies on analytical procedures for the measurement of the fumonisin content.