OBJECTIVE: To learn about parent, nurse, and family physician attitudes toward multiple simultaneous childhood vaccinations. DESIGN: Survey. SETTING: Thirty-two family practice clinics in Minnesota. PATIENTS/PARTICIPANTS: Forty-six volunteer Minnesota Academy of Family Physicians Research Network members, 42 of their nurses, and 342 parents of their patients aged less than 6 years who have had at least one injection. MAIN OUTCOME MEASURES: Number of injections believed to be too many for a child to receive simultaneously and comfort level associated with children's receiving three simultaneous injectable vaccinations. RESULTS: Most parents, nurses, and physicians (71%, 76%, and 59%, respectively) think that three injections are too many for a child to receive at one visit. Similar percentages of parents, nurses, and physicians are uncomfortable with a child's receiving three injections at one visit. Sixty-seven percent of the physicians who do not offer universal newborn hepatitis B vaccinations cite the number of required simultaneous injections as a factor in that decision. Only 15% of physicians order all three recommended injections for most of their 15-month-old patients. CONCLUSIONS: Most parents, nurses, and physicians are uncomfortable with three simultaneous injections for children. This discomfort may be a significant barrier to the adoption of the new immunization recommendations. The development of effective combination vaccines should be a research priority.