In the years 2002-2005, at the Experiment Station of the Faculty of Agriculture at Mochełk, a two-factor field experiment was performed to define and to compare the forecrop value of spring cereals: barley, oat, wheat, triticale and fallow for winter forms of wheat and barley. To evaluate the main effects and the interactive effect of forecrops on the yielding components and the grain yield of winter cereals, irrespective of the variation in the research years, there was used a mixed model of the analysis of variance and the Tukey significance test. The variation in the winter wheat and winter barley characters over years and as affected by the forecrops was evaluated with the coefficient of variation. Winter wheat reacted to the forecrop more strongly that winter barley, yielded best on the stand after oats, and worst – after triticale and wheat. These forecrops, however, did not differentiate the yield of winter barley. Winter wheat yield was more stable over the years than winter barley. The least variable yields of both winter barley and winter wheat were recorded on the stand after spring wheat. The forecrop value of fallow for both winter cereal species was low and similar to the forecrop value of spring forms of triticale and wheat.