The prevalence of tooth wear was assessed in a random sample of 14 year old school children in Liverpool. A total of 1035 children were examined in 10 schools of whom 526 (50.8 per cent) were male and 509 (49.2 per cent) were female. Three hundred and seven children (30 per cent) had exposed dentine, mainly incisally, and this occurred significantly more often in males than females (P < 0.01). Of these children, 80 (8 per cent) also exhibited exposed dentine on occlusal and/or lingual surfaces. This occurred mainly on the occlusal surfaces of the first mandibular molars and the lingual aspects of the upper incisors. A slight positive association was found between tooth wear and the level of social deprivation in the electoral ward in which the school was located.