Some 139 advanced breeding lines with improved agronomic characters derived from crosses involving tungro-resistant rice varieties were evaluated for resis- tance to rice tungro viruses under greenhouse conditions. These lines consistently showed a resistant reaction to tungro under natural field infection in the tungro nursery at IRRI for at least six growing seasons. In the crosses, Utri Rajapan, Utri Merah, ARC11554,Habiganj DW8, and wild rices Oryza longistaminata and O. rufipogon (accession no. 105908 and 105910 and one with an unknown accession no.) were used as sources of resistance to tungro, whereas IR1561-228-3-3, IR24, and IR64 were used as the recurrent parents. Except for ARC11554, O. longistaminata, IR24, and IR64, all the other parents are susceptible to the virus vector green leafhopper (GLH).