Tobacco veinal necrosis disease caused by Potato Virus Y strain T (PVY-T), a strain new to Japan, has been becoming a more and more serious problem, since the first cases in Japan were reported some 15 years ago. Presently, this disease causes significant economic losses in tobacco production areas throughout Japan. Here we report the breeding of PVY-T resistant tobacco varieties suitable to Japan. About 700 tobacco (N. Tabacum) varieties were screened for the resistance to PVY-T, and 69 of them showed various levels of resistance. The resistant varieties fell into three classes, high-level, medium-level, and low-level class. A genetic analysis revealed that the resistance of each class was controlled by a single recessive gene, and all resistant genes so far studied were allelic. In addition, the PVY-T resistance of 2 varieties Virgin A Mutant and Enshu, was linked to the low production of leaf surface diterpenoids. Several pairs of isogenic lines regarding the PVY -T resistance of various sources were developed. Side effects of the resistant genes were estimated by investigating the field performances of these lines. From these data, we selected Perevi, Virgin A Mutant, Bursana and Enshu as the best sources of PVY-T resistance. The PVY-T resistance of the selected sources was introduced into the major tobacco varieties in Japan, including 7 flue-cured, 2 Burley and 4 domestic varieties.