Fifteen maize inbred lines were evaluated for resistance to ear rot, using artificial inoculation of plants with isolates ofStenocarpella maydisfrom 13 localities in the South African maize production area. Five inbreds and four isolates were common to the four seasons of evaluation. The inbreds B37, D0620Y and E739 showed levels of resistance superior to that of the standard Hill. Isolates provided inconsistent infection levels in different years. All interactions were significant, with seasonal effects predominating over the genotype x isolate interaction.