Based on the Third National Cancer Survey (1969 to 1971), the incidence of malignant neoplasms in the United States was 183.4 per million live births per year in infants younger than 1 year and 36.5 in newborns younger than 29 days. In both age groups, neuroblastoma was the most commonly diagnosed neoplasm. Overall, cancer incidence in infants younger than 1 year was almost 3.5 times greater than mortality determined from US death certificates from 1960 to 1969. For individual tumor types, the ratio between incidence and mortality varied between 159 for retinoblastoma and 1.5 for leukemia largely reflecting relative differences in survival due to treatment.