The materials obtained from CIMMYT, ICARDA programmes and various countries, together with advanced breeding lines and registered spring and winter wheat cultivars have been tested for resistance to BYDV. Field infection trials performed in 2002-2006 period contained infection and uninfected variants. The plants were grown on two-row plots 1-m long with two replicates. Infection with PAV strain of BYDV was carried out at the beginning of the tillering stage. Bird cherry-oat aphids (Rophalosiphum padi) obtained from greenhouse rearing were used for virus transmission. The intensity of the symptomatic response was classified according to a 1-9 scale at the phase of full flowering. The effect of virus infection on yield components was assessed after plant harvesting, when the susceptibility index (SI) was also determined. New sources of resistance were detected also in winter wheat. However, a wider choice of resistant genotypes still offer spring types. There were detected some highly resistant spring wheat materials with still unknown resistance genes (e.g. WKL-91-138, Kivu-85, QG2.1 and QG4.37). It was also found that either Bdv1 or Bdv2 need not guarantee obtaining desirable resistance level. Progress can be reached by combining these resistance genes (using MAS). Owing to high differences in response of Bdv1 and Bdv2 gene carriers to BYDV, it is evidently necessary to identify and exploit also the other BYDV resistance genes.