The epidemiology mid histology of Hodgkin's disease in Cali, Colombia is reported on the basis of data from the Cancer Registry and a review of slides from several of the city's departments of pathology. Comparison of the results with incidence data published by UICC and with other reports on histologic subclassification has led to the identification of several epidemiologic patterns. Pattern I is characterized by high rates in children and predominance of histologic subtypes associated with poor prognosis. Pattern III is characterized by high rates in young adults and predominance of histologic subtypes associated with better prognosis. Pattern II is intermediate. These patterns are related to the economic stratification of the communities studied, and it is suggested that many of the epidemiological variegations of Hodgkin's disease may be explained on the basis of the interplay of environmental and host etiologic factors.