In connection with the recorded spread in Poland of a tobacco disease manifesting itself by stem rot, in the years 1984-1986, a series of tobacco cultivars and wild species were evaluated for resistance to the disease (Botrytis cinera Pers.). The tests were carried out in a greenhouse, using artificial infection of plants. From among 60 cultivars, none was resistant to the pathogen the varieties differed in the degree of susceptibility. The degree of infection of the plants was influenced among others by their stage of growth as well as by the virulence of the race of the pathogen. Six-week-old seedlings, when inoculated, showed more severe infection than eight-week-old seedlings. From among the tested series of wild species, four proved resistant, that is, N. rotundifolia, N. nudicaulis, N. langsdorffii and N. knightiana. These species are being used in the breeding programme for resistant varieties.