Background: There has been no previous incidence survey of children referred to a speech and language therapy service in the UK. Previous studies of prevalence of specific communication difficulties provide contradictory data from which it is difficult to plan speech and language therapy service provision. Reliable data are needed concerning the nature and severity of impairments as well as the age and source of referral and the effects of cultural and socio-economic profiles of the population served. Aims: To describe referrals received between January 1999 and April 2000 by the paediatric speech and language therapy service of Middlesborough Primary Care Trust, an area of social deprivation. Methods & Procedures: All referrals were offered an initial assessment appointment within 8 weeks of referral. Standardized tests and quantitative measures of communication difficulties, determined by age, were undertaken. Population and case history information was also gathered. Outcomes & Results: The incidence rate of referrals who attended for assessment in a single year was calculated as 16.3% for primary communication disability and 14.6% for speech/language disability. Of the 1100 referrals, 14.9% failed to attend and 9.8% had normal functioning. The distribution of disorder type was dysfluency 5.3%, voice or nasality disruption 2.0%; receptive language difficulties 20.4%, expressive language difficulties 16.9% and speech difficulties 29.1%. A further 0.7% had special educational needs and 0.9% had speech and language impairment but refused consent. The majority of referrals were between 2 and 6 years old, more boys than girls were referred, and socio-economic status matched that of the local population. Both gender and socio-economic status affected diagnosis. Conclusions: Based on the Middlesborough data, the estimated national incidence rate of referrals who attend for assessment and who have speech and language disability is 85000-90000 children per year (14.6% of births). While findings from only one Primary Care Trust must be treated cautiously, they provide paediatric speech and language therapy services managers with information that might guide service planning.