Necrotic strains of potato virus Y (PVY), the pathogen responsible for tobacco veinal necrosis, cause substantial losses in tobacco yield and quality. Last year as part of the PVY Collaborative Experiment coordinated by CORESTA, resistance to PVY was evaluated for the CORESTA collection of tobacco test cultivars. The survey showed the occurrence, under natural infection conditions, of the strain PVY^N. The strain infected cv. NCTG, breaking "VR" resistance, which situates it close to French "type 2". The strain failed to overcome "va'' resistance in cvs. VAM and V.SCR. It infects some potato varieties without causing necrotic lesions in the tubers. PVY collection in Pulawy has two more PVY strains: virulent necrotic Y^NZ, isolated in 1971, and Y^NIII, isolated from tobacco in 1995. All test varieties became infected and developed severe veinal necrosis following mechanical inoculation with strain PVY^NZ. The strain overcame "va'' and "VR'' types of resistance. It is similar to the French type designated as "type 3'' with regard to necrotic responses of the affected test cultivars. The incidence of the strain in the field is very low. It does not affect potatoes. The symptoms caused by PVY^NIII on the test genotypes are different from those produced by the strains Y^N and Y^NZ. The isolate causes necrotic lesions on affected potato tubers which makes it close to the Y^NTN group. All the strains reported in the paper are detectable in ELISA tests by a polyclonal antibody from the Potato Institute in Gdansk.