Common bunt (Tilletia tritici) infects the wheat plant during germination of the seed. For experiments with common bunt, it is conventional to examine symptoms of infection in the head of the plant. Previous research has advocated the possibility of scoring chlorosis on the leaf instead of head symp-toms in order to reduce the duration of the experiment. By comparing the two diagnosis methods in climate chambers, the current experiment demonstrated that the sensitivity and specificity of the two methods depends on the wheat cultivar used. Using leaf symptoms as a diagnosis for infection has considerable disadvantages when used for screening for resistance in breeding programs, but have advantages, e. g., when investigating effects of seed treatments.