We conducted a randomized, double-blind trial to evaluate the safety and tolerability of a live attenuated cold adapted trivalent intranasal influenza vaccine, FluMist, compared with intranasal placebo when given in addition to a licensed trivalent injected inactivated influenza vaccine (TIV). The study population consisted of persons 65 years of age and older with chronic cardiovascular or pulmonary conditions or diabetes mellitus. During the 7 days post-vaccination, sore throat was reported on at least one day by 15% (15/100) of FluMist recipients compared with 2% (2/100) of intranasal placebo recipients (p = 0.001). No other reactogenicity symptom was statistically associated with receipt of FluMist. Among this group, FluMist was safe and well tolerated when administered with TIV.