['To investigate the relationship between heavy daily smoking and suicidality among adolescent psychiatric inpatients in Finland.', 'Data were collected from 411 patients (age 12-17 years) admitted to inpatient psychiatric hospitalization between April 2001 and July 2005. The number of daily cigarettes (>15) and the time of first cigarette after waking up (within 30 min) were used as indicators of heavy daily smoking.', 'After adjusting for psychiatric diagnoses an over twofold risk for suicide attempts was found among adolescents who smoked over 15 cigarettes a day. Additionally, if an adolescent also smoked the first cigarette immediately after waking up the risk was over threefold. Suicidal ideation was not associated with smoking behaviour.'] Is heavy daily smoking among under 18-year-old psychiatric inpatients associated with increased risk for suicide attempts?