To determine the prevalence of otitis media with effusion (OME) in children with Down syndrome (DS), and the associated to hearing loss at the age of 8 years.A national population based clinical study of all children with DS born in Norway in 2002.OME was found in 20 out of 52 (38%) children. Those with OME had a significant lower hearing level with a mean pure tone average (PTA) of 33.4 dB HL compared to children with no OME whose mean PTA was 21.7 dB HL (p0.0001). Verified hearing loss above 25 dB HL in the better hearing ear was found in 12 out of the 20 with OME, compared to 5 out 31 without OME.The findings of this present study uncover the increased risk of OME in eight year old children with DS as current otitis media was found in one of three. This reduced hearing ability in children with DS due to OME at age of 8 strongly emphasizes the need for optimal treatment and follow up to optimize hearing rehabilitation. The findings are further supported by the population based study design, the focus on the narrow age band and the high response rate.