OBJECTIVE To study the behaviour/emotional problems and depression in adolescents with and without physical illnesses; to compare the same psychological parameters in adolescents with different disorders. METHODS The sample consisted of 148 adolescents aged 13-16 years with one of the following physical chronic conditions: diabetes (n = 55), asthma (n = 59), or epilepsy (n = 59). Comparative data were obtained from a group of 301 schoolchildren. Test batteries (Child Behaviour Check-List, Youth Self Report, Beck Depression Inventory, socio-economic status questions) were individually completed by adolescents and their mothers. RESULTS Overall adolescents with physical illness had more behaviour/emotional problems and were more depressed compared to controls although results varied according to the informants and the disease severity. Two risk groups were revealed: girls with asthma and boys with epilepsy. CONCLUSIONS Our results suggest that mental health in adolescents with chronic physical illnesses is poorer than in controls and their mental health state is very much associated with the disease severity. The findings of the study can help to develop disease targeted and comprehensive interventions in outpatient clinics of Northern Russia in order to reduce behaviour and mood disorders in adolescents with chronic physical illnesses and therefore to smooth the transition through their teenage years.