A questionnaire study was done in June and August, 1987,in Saga City, Japan, to know the frequency of mosquito bites, prevalence and effects of anti-mosquito measures, and citizens' view on mosquito problems. Mean numbers of bites were 0.99 (June) and 0.95 (August) per day per person staying at home throughout the day, with maximums of 9 (June) and 14 (August). Three quarters of those persons received 1 or less bite per day. More (64%) bites were received during the daytime (sunrise to sunset). Of daytime bites, 60% were outdoors, whereas 70% were indoors at night. The number of bites outside home (offices, schools and so on) was much fewer than that at home. Seventy percent of houses were equipped with screens at all windows. The most popular anti-mosquito measure was electric-heating insecticide mats followed by insecticide sprays and mosquito coils, whereas mosquito nets were used in only 15% of houses. Window screens reduced the number of indoor bites, whereas the frequency of use of antimosquito measures positively correlated with the number of indoor bites, suggesting that insecticides were used after mosquito bites rather than a preventive measure. Persons receiving more mosquito bites had stronger attitudes toward mosquito control by the public service. More than a half of persons receiving 2 or more bites per day considered that the mosquito problem was intolerable and the control is necessary. As a whole, 42% of persons regarded the mosquito problem tolerable, whereas 41% regarded it intolerable, with only 3% who regarded mosquito problems negligible (the rest did not give answer to this inquiry).