The First National Health and Nutrition Examination Survey (NHANESI), conducted in 1971-1975, included a cohort of 6913 adults for whom history of smoking, allergies, and other factors was obtained. These persons were traced (with 93% success) approximately 10 years later by the NHANESI Epidemiologic Followup Survey, and incidence of malignancy in the interim period was determined. Primary allergy variables were physician-diagnosed asthma, hay fever, hives, food allergy, or other allergies. Excluded were persons with a prior history of cancer and cases of nonmelanoma skin cancer. After adjustment by logistic regression for age, sex, race, and smoking history, allergic history was found to increase the risk of subsequent malignancy (risk odds ratio = 1.40, 95% confidence interval = 1.10-1.77). The specific allergy type with the strongest cancer risk was hives. The cancer group with the strongest allergy association was lymphatic-hematopoietic (leukemia, lymphoma, myeloma). The risk odds ratio of developing leukemia, lymphoma, or myeloma for persons with hives history was 7.89 (95% CI = 3.13-19.89). These findings suggest that a history of allergy does not protect against subsequent cancer, and may be a risk factor. The possibility is raised that a history of hives may be a particular risk factor for lymphatic-hematopoietic malignancies.