In the present study, which was carried out in peri-urban areas of Lima and Chimbote, Peru, and La Paz, Bolivia, the household survey method was used to investigate the manner in which drugs are used in treating the most common diseases in each locality. The objectives were to detect inappropriate practices, correct them through educational interventions, and determine the interventions' effectiveness. Simple random sampling was used to select the residences surveyed, which were then divided into study groups and control groups. A preliminary survey determined that the most frequent illnesses were the common cold, diarrhea, and dietary deficiency diseases and that their treatment often involved the inappropriate use of drugs. Educational interventions of varying duration were carried out, and subsequently a second survey was performed using the same instrument in order to determine the effectiveness of the interventions. Although there was an increased tendency not to treat the aforementioned diseases, the responses directly related to the use of drugs did not reveal any significant changes in behavior. Various factors were identified that influence the consumption of drugs.