BACKGROUND: We have interviewed the parents of children born at two maternity hospitals to evaluate the knowledge of parents concerning the French Huriet law and their consent to the participation of their child in a randomized therapeutic trial. METHODS: The inquiry was conducted between 15 February and 30 April 1991. Each couple of parents of whom the mother had given birth in one of the hospitals was sent an explanatory letter and a questionnaire on the second day after delivery. Parents who were unable to read adequately and those whose baby was ill were excluded from the study. The main questions were: age of parents, country of origin, education, profession, social insurance, frequency of medical consulting, their knowledge of the Huriet law, the source of that knowledge, their attitude to giving parental consent for their child to participate in a trial, the reasons for their consent or refusal. RESULTS: Five hundred and eighty two questionnaires were distributed but only 541 were used. 73% of the parents said they knew that drugs were tested on volunteers. 59% claimed to know of the Huriet law, through the media (75%), their practitionist (12%), their environment (8%). 21% of the parents would consent to one of their children participating in such trial; 74% would refuse. Both parents were in agreement in 79% of cases, 12% of them for consent. The main reasons for refusal were the risk for side-effects of the drug (75%), lack of proof for efficacy (49%), disagreement in principle (19%). The mothers who consented were older than those who refused. The members of the "consent" group were more highly educated. CONCLUSIONS: Law Huriet is still inadequately understood in France. Pediatricians should consider how best to provide parents and the media with better information before trying to obtain parental consent.