Six cases of nasopharyngeal carcinoma (NPC) were diagnosed in residents of Bermuda in the 7-year period 1966-1972. While epidemiologic study revealed no history of common environmental exposures, two of the six cases occurred in adult sibs from a family in which a third adult sib developed NPC in 1963. These three cases were from a large, possibly in-bred Portuguese family with origins in the Azores Islands. The remaining four cases were all in black children ages 10-15; two of these were first cousins. These observations suggest the possibility that genetic influence may contribute to the etiology of NPC.