The aim of this review was to identify whether, in children under 2 years of age, pacifier (dummy) use results in an increased risk of ear infection (acute otitis media). The Cochrane Library, Medline, CINAHL and Embase databases were searched for cohort studies and randomised controlled trials that compared infants who used pacifiers with those who didn't or examined the effect of reducing pacifier use in a group of infants. One cluster randomised trial and two cohort studies met the review criteria and were available to be included in the body of the review. These studies show a clear increase in risk of ear infection to be associated with use of a pacifier that may well be causal. The risk of ear infections is up to three times higher in those who use a pacifier and there does appear to be a 'dose response' with continual users more at risk than occasional users. However, this relationship may be confounded by socio-demographic factors. Rather than advising a parent not to use a pacifier for fear of causing otitis media, advice in relation to this issue might best be restricted to pacifier users suffering from the problem in order to reduce the chances of recurrence.