A cluster sample of 2,052 mothers and other caregivers of children from southwest Nigeria was studied. Qualitative and quantitative methods of data collection were employed, including semi-structured questionnaires, focus groups, in-depth interviews, and parasitological investigation forms/blood smears. "Too much work" (17.7%) and "too much sun" (12.6%) were the two most-often mentioned causes of malaria. Malaria was not perceived as a serious disease. Convulsions and anemia are not perceived as complications of malaria and are preferentially treated by traditional healers. Fifty-eight and one-half percent of children with malaria were treated at home. Choice of drugs used was based on previous experience and advice from various members of the community. Fathers (53.5%) and mother (32.5%) decided on where ill children received treatment. Mothers (51.5%) paid for the drugs more often than fathers (44.6%). Symptoms described as "iba lasan," which means "ordinary fever," conform to the clinical case definition of malaria. Cultural practices that are likely to influence appropriate treatment-seeking include cultural perception of malaria as ordinary fever, wrong perceptions of severe malaria, and father's role as decision maker.