In the city of Guangzhou (Canton) and its surroundings nasopharyngeal cancer (NPC) constitutes about 32% of all cancer and is therefore the most common kind of cancer. Three types of etiological factors seem to be involved: 1) a hereditary factor, 2) Epstein-Barr virus, and 3) external factors in food and water. An epidemiological study has been started in the Guangzhou area with interviews of NPC cases, matching controls and mothers of the cases and controls concerning especially food and environmental factors and infections in childhood. The questions put to the controls and cases covered the last seven years and the age of ten, while those to the mothers covered the first three years of life and the age of ten for the controls and cases. Results are now available for 140 cases, 140 controls and the corresponding living mothers. They indicate that salted fish, particularly of Cantonese style, was consumed more by NPC cases than by controls and also had more frequently been given to weaning children in whom NPC later developed. Furthermore, salted vegetables and salted pork were consumed to a greater extent by NPC cases than by controls. Drinking of polluted water in childhood was more common among the NPC cases. Consumption of fresh fruit was more rare among the cases. Most of the NPC cases had a positive VCA-IgA titre.