Forty-two patients with a history of egg sensitivity were evaluated for receiving avian-grown vaccines. After giving a history and undergoing physical examination, each patient was skin-tested with egg antigens and six egg-propagated vaccines, given an oral egg challenge, and finally, when possible, given a vaccine challenge. Thirty-seven of the 42 patients (88%) were ultimately given one or more of the vaccines with no reactions or only minimal ones to both egg protein and vaccine; they had mild reactions consisting of pruritus, headache, and apprehension. Immunization was withheld from three patients who had a history of severe reactions after egg ingestion and strongly positive skin reactivity to both egg and vaccine. A history of egg intolerance should not, by itself, disqualify a patient from receiving one of these vaccines. However, a history of exquisite sensitivity to egg protein indicates that a severe vaccine reaction is likely. An intradermal skin test utilizing 0.02 ml of a 1:100 dilution of the vaccine and resulting in a wheal of greater than 5 mm was found to be the test that most reliably predicted those patients who should not receive the vaccine.