We compared the social class characteristics of 66 families with children diagnosed with Hodgkin's disease (HD) from 1959 through 1977 in a defined population with that of 182 "control families" identified by a random process from the population base. The 14 youngest cases (less than 10 years at diagnosis) were from somewhat lower social-class backgrounds than their 37 controls as evidenced by the distribution of median income, single-unit housing, and poverty level of their census tract of residence, as well as by the occupational class of head-of-household. In contrast, the social class characteristics of the 52 older children with HD (10-14 years) were quite similar to that of their 145 controls. This apparent shift from lower to average social class between younger and older children with HD Hodgkin's disease may reflect a shift in their age of exposure to common infections. If true, these findings are consistent with the hypothesis that HD may develop as a rare consequence of a common infection. However, these findings are based on small numbers of cases and on indirect measures of social class.