The aim of the study was determination of the effect of differentiated nitrogen fertilization and the variety of winter oilseed rape on the results of spectral measurements, and estimation of the opportunities of yield forecasting on the basis of reflectance factors and vegetative indices. Measurements of spectral radiation from the plants were carried out with the use of radiometer CE 313 (Cimel Electronique Co.) and evaluated in the form of three reflectance factors (SWO650, SWO850, SWO1650) and three vegetative indices (NDVI – Normalized Difference Vegetation Index, RVI – Ratio Vegetation Index, ELAI – Estimated Leaf Area Index). The conducted experiments proved significant differences between plots sown with different plant varieties and fertilized with different doses of nitrogen. Differentiation of plant development under the influence of nitrogen fertilization was shown in the phase of full budding of oilseed rape using all analysed reflectance factors and vegetative indices, as well as at the beginning of the phase of silique development. High correlation between the values of spectral measurements carried out in the phase of full budding of oilseed rape and the yield of seeds, and convergence of the differentiation of the spectral characteristics and the yields obtained from experimental combinations indicate the possibility of applying spectral measure-ments in estimation of the status of crop cultures and in forecasting of winter oilseed rape yield.