Several important issues regarding chemoprophylaxis for H. influenzae type b infections should be resolved before general adoption of the recommendations of the Committee on Infectious Diseases. Unfortunately the recommendations place the practicing pediatrician in a medical-legal dilemma if he does not comply. The prematurity of the recommendations may preclude further placebo-controlled, prospective evaluation of the efficacy of rifampin or other agents in the prevention of secondary disease. In any event the administration of chemoprophylaxis must not replace close surveillance of all members of the contact group. Band et al. estimated that 150 to 200 of the approximately 20,000 cases of invasive H. influenzae type b disease that occur each year in the United States may be preventable by prophylaxis. Primary prevention with a safe effective vaccine would have a much greater impact.