Characteristics for workers hired to main plants of Mayak PA in 1948–1982 are presented. Extended registry includes 22,347 individuals. As of 31.12.2000, vital status has been ascertained for 92% of cohort members, of which 37% died. External gamma-exposure doses are known for 83% of cohort members; the average value of external exposure dose is 0.7 Gy. Plutonium body burden was measured in 39% of workers, and the average value of plutonium body burden is 1.7 kBq (including values below the sensitivity threshold). Excess relative risk of mortality due to solid malignant neoplasm is 0.2 per Gy, and 1.9 per Gy for leukaemia. Lung cancer comes first in the list of cancer-related death causes.