Pneumococcal vaccines may be effective in preventing or decreasing the burden of disease related to otitis media. In study reported here, we investigated the effectiveness of pneumococcal vaccination on otitis media with effusion (OME) in children (n = 383 children aged 1-7 years) with a history of recurrent otitis media within the framework of a randomized double blind placebo controlled trial. Children were randomized to be immunized with either a 7-valent pneumococcal conjugate vaccine followed by the 23-valent pneumococcal polysaccharide vaccine, or by hepatitis A or B vaccines. The proportion of children diagnosed with OME at the scheduled follow-up visits--7, 14, 20 and 26 months after randomization--was then calculated. OME was diagnosed according to an algorithm combining tympanometry and otoscopy. The percentage of children diagnosed with OME was similar in the pneumococcal vaccination group and control group at both baseline and the follow-up visits at 7, 14, 20 and 26 months--52.9 versus 52.7, 44.9 versus 44.2, 34.9 versus 31.5, 40.8 versus 32.2 and 31.4 versus 26.1, respectively (corresponding to p-values of 0.96, 0.89, 0.51, 0.13 and 0.36, respectively). We conclude that the combined pneumococcal conjugate and the polysaccharide vaccination have no beneficial effect on OME in children aged 1 year or older with a history of recurrent otitis media. Therefore, these vaccinations are not indicated in the prevention of OME in these children.