This study compared cancer mortality among the Seneca Nation of Indians (SNI) between 1955 and 1984 with cancer patterns exhibited by the general population of New York State (NYS), exclusive of New York City. Cancer mortality among the SNI was compared with cancer mortality in NYS using age and sex standardized mortality ratios (SMR). Deficits in overall cancer mortality were noted among both SNI males (SMR = 78) and females (SMR = 73). Results from this investigation will contribute to the understanding of patterns of malignant disease mortality among native peoples and may be of benefit for monitoring the impact of cancer mortality among the SNI and other Native American groups.