Hodgkin's disease diagnosed among 1,633 Connecticut residents during 1940–69 was studied systematically for the presence of 1- and 2-year clusters. To eliminate the effects of increases in incidence of the disease and changes in the composition of the population, 1940-69 was studied as 6 contiguous 5-year groups. The data indicated some clustering, though not highly significant, for 1950–54 and 1955–59. A more uniform distribution of cases than expected for 1965–69 was also indicated. No real evidence of clustering for the entire study period was apparent.