Investigation of chlorophyll meter values of 13 winter wheat cultivars suggests that readings are dependent on cultivar (genotype), growth stage and years effects. Before 2 nd top dressing at the stage EC 31/32 the average value varied from 445 to 568, and before 3 rd top dressing at the stage EC 45/50 it varied from 487 to 580. At the stage EC 45/50 the statistically identical values of six cultivars varied from 515 to 553, with the rest the extreme readings were 487 or 580. At the stage EC 31/32 there was no strong correlation (r=0.134) between chlorophyll meter readings and grain yield, but there was stronger correlation between the chlorophyll meter values and grain yield (r=0.538, sig. at the 0.01 level) at the stage EC 45/50. On the basis of results at the stage EC 45/50 only it is possible to explain 37% effect of the chlorophyll meter readings on the grain yield with quadratic or cubic regression curve.