Leukemia (51: 1988-1998) and thyroid cancer (106: 1991-1998) incidence in children and adolescents after Chemobyl accident in Bryansk region was assessed. A significant increase over spontaneous incidence in the same category of population and during the same period was reported. Standardized thyroid cancer incidence for the region is 5.37 times the federal level (95% confidence intervals--4.40 and 6.49, respectively); the upward trend is significant. The same trend is characteristic of leukemia incidence/exposure dose correlation but is not significant. Standardized leukemia incidence is 1.04 times the federal level (95% confidence intervals--0.78% and 1.34, respectively), and tallies with the federal level, within the margin of error. The findings are clearly indicative of exposure to radiation being a factor of higher thyroid cancer incidence in children and adolescents in Bryansk region.