Our aim was to evaluate effectiveness of pandemic influenza A/H1N1 vaccine in preventing acute otitis media (AOM) and/or otitis media with effusion (OME), in a randomized, prospective and single-blind study conducted in the children aged of 6-60 months. This study was done between December 1, 2009 and April 30, 2010 during the pandemia between June 2009 and May 2010. On the healthy children, vaccinated against pandemic influenza A/H1N1 and age-matched unvaccinated controls, the rate of AOM, OME, and any otitis media (OM) attack (sum of AOM and OME attacks) confirmed by otoscopic and tympanometric examination, and their associations with risk factors were looked for. Otoscopic and tympanometric evaluation was done twice within the follow-up period of 4-8 weeks. Totally 46 vaccinated and 46 unvaccinated healthy children were enrolled. No difference in rates of AOM, OME, or OM was found between vaccinated and unvaccinated children. But logistic regression analysis revealed that unvaccinated children had 2.9-folds more risk for OME and OM, but not for AOM. Further, male gender and bottle feeding and/or using pacifier revealed significant relationships with AOM. Conclusion: We conclude that pandemic influenza A/H1N1 vaccine prevented OME rather than AOM attacks in children with 6-60 months of age.