Two randomized studies were performed in 1992 and 1994 in the Niger river valley where malaria transmission is thought to be permanent and is reinforced during the rainy season. The sample covered 114 families either in Niamey, the capital of Niger, or in Karma, a rural village 20 km to the west, and its surroundings. The questionnaire contained closed and open questions on the perception of malaria causes, treatment and prevention, including the use of mosquito bed nets. Most of the 114 families studied were monogamic with an average of 4 children per father. The most frequent occupation was agricultural farming (millet and rice) for the sedentary part of this population. During the rainy season, some moved to farms in the neighbouring valley of Taksaba. During the wet season, others migrated to the West African coast. The houses were traditional, being straw huts or made from banco; all the openings were small the the rooms were dark and poorly ventilated. These features constituted good conditions for malaria vectors. Domestic animals, such as goats, sheep, cows and sometimes donkeys, were very frequent in the courtyards. However, there was never any stagnant water in the courtyards or around the water pumps because of the intense sunshine. Drinking water was carried on the head from the public foot pumps or the river and stored in earth calabashes closed by a plate. In the Songhay-Zarma language, Hémar Izé is a symptomatic complex which corresponds closely to a clinical case of malaria. The main sign of this complex is fever known as konni (hot body). But this word is also used as the general name for all diseases with fever. Associated symptoms, well known by the community members, included vomiting, headache and diarrhoea. Hémar Izé was considered to be the most frequent cause of morbidity and the most severe disease, more significant than any other fever or diarrhoea. As perceived by the community members, the leading cause of malaria was described to be mosquitos (44.7%), followed by the rainy season, God, and less commonly, dirtiness, parasites, or the sun. The majority of cases were diagnosed by the parents, and were self-treated at home either with medicinal plant infusions or oral drugs. The self-treatment was not common, because Nivaquine was the only medication known by the people and was often unavailable. It is necessary to manage a regular drug supply with a public awareness campaign about dosage for self-treatment of malaria. Also, the public needs to be informed about any new policies of supplying essential drugs under generic names. Despite some confusion, the people generally believed that mosquitos were responsible for the disease. Thus, the use of mosquito netting over the beds was justified and widespread throughout the population. The traditional practice could be improved upon with an impregnated net even if the comprehension about the causes of the disease remains limited.