In this register study the epidemiologic features of Hodgkin's disease (HD) in Cuba and Sweden during 1964-1981 are compared. HD in the adult (greater than or equal to 15 years of age) is more common in Sweden than in Cuba (age-standardized incidence rate 3.6 X 10(5) vs. 3.1 X 10(5) but for childhood HD the opposite is true (2.1 X 10(5) vs. 3.0 X 10(5). In both countries a male predominance is found. A decrease in the incidence of HD is noted only in the Swedish population after 1973. The study reveals a stable bimodal age incidence pattern in Sweden but a shift from a linear increasing to a bimodal incidence pattern in Cuba, which parallels the Cuban development from an agricultural to an industrialized country.