A study on the incidence of nasopharyngeal carcinoma (NPC) has been performed in the Provence-Alpes-Côte d'Azur (PACA) region, South of France, where Maghrebian migrants represent 10% of the population. During the years 1986-1990, 76 cases of NPC were diagnosed, of which 44 were French by birth, 25 were Maghrebian migrants and 7 were other migrants. We found that 36% of the French patients were either born in endemic areas or had lived there for more than 15 years. Standardized annual incidence rates of NPC among Maghrebian migrants remained close to those observed in North Africa, while, standardized annual incidence rates for French by birth in the PACA region were similar to those observed in cancer registries in other regions of France and countries of low incidence. However, for males of French origin born in Maghrebian countries, the incidence of NPC (all cases being of undifferentiated type) was 5.7 times higher than that of males of French origin born in France (p = 0.00001). These results favor a critical role of environmental factors in the risk of NPC.