Background The paediatric population is known to be at high risk for psychiatric problems. Paediatric liaison child/adolescent mental health services (PL‐CAMHS) have been developed to help increase recognition and management of psychiatric morbidity in the paediatric setting. This report describes clinical activity by a psychological medicine PL‐CAMHS and considers specificity by comparing this with community/general CAMHS activity. Method Clinical information was obtained on consecutive patients seen by a PL‐CAMHS in a UK tertiary specialist hospital. Where feasible this was compared with published data on national/community CAMHS work. Results Data was obtained on 800 patients (mean age 11.9, SD 3.8). Most referrals came from a variety of paediatric teams, nearly two‐thirds were for psychosomatic problems or difficulties adjusting to physical illness. The majority had an ICD‐10 psychiatric diagnosis (mostly adjustment, mood and anxiety, and somatoform disorders); problems were often complex and in about half, family difficulties were also noted; one‐third had received prior mental health treatment. Virtually all children were seen by the PL service within a month of referral and only 2% of families failed to attend for assessment. Some level of clinical improvement was noted for the majority. There were indications of differences from national/community CAMHS work in referral source, take up rates and psychiatric diagnoses. Conclusions Paediatric liaison child and adolescent mental health services users commonly have characteristic psychiatric problems, interventions appear potentially effective and the work is specific and complementary of community CAMHS. Thus PL‐CAMHS make a distinct contribution to the provision of truly comprehensive CAMHS.