A survey was conducted in a general pediatric practice to determine parents' attitudes to and compliance with the recommended Haemophilus influenzae type b vaccine program. Of 133 families surveyed 127 (95%) responded to the questionnaire. About one third of the parents did not have their children vaccinated. The decision against vaccination was made despite parent education, follow-up telephone contact and the pediatrician's expressed support of the vaccine program. Most of the respondents (86%) had no previous knowledge of the vaccine. The factor of greatest concern was the possibility of an adverse reaction. This concern was significantly more common among the parents who decided not to have their children vaccinated than among those who had their children vaccinated (chi 2 = 6.52, p less than 0.025). One third of the parents who indicated that they intended to have their children vaccinated required a telephone reminder. The findings suggest a need for public education about the vaccine, with particular emphasis directed at allaying fears about side effects.