Sixty-four urban children grades K-6 were interviewed in an exploratory study in 1980 to provide information about children's knowledge and orientations toward medicines and abusable substances. Responses indicated children believe themselves to have considerable autonomy in medicine use - 72% said they ask for medicines, 67% get medicines for themselves and others, and 19% (more often older and less economically advantaged) buy medicines by themselves. For six of eight common health problems, e.g. colds, headaches, children said they were more likely than their mothers to take something special; for nervousness and trouble sleeping, mothers were perceived as more likely. Most children distinguished among health problems when indicating probabilities, and many distinguished between themselves and their mothers when naming specific medicines. Children exhibited considerable misinformation and confusion about medicines and "drugs", e.g. one-third of the children said medicines and drugs were the same thing, while nearly one-fifth said they were not. Sixteen percent of the children said "bad drugs" come from commercial establishments such as drug stores. Children might benefit from efforts to provide them integrated information about medicines and abusable substances, and to deal with questions and anxieties provoked by the mixed messages they receive from adults and society. In view of the amount of autonomy indicated, physicians might increase children's compliance with medicine use by addressing the child as well as the parent. A larger study of 420 children is underway.