BackgroundSuicide prediction during psychiatric in-patient treatment remains an unresolved challenge.AimsTo identify determinants of railway suicides in individuals receiving in-patient psychiatric treatment.MethodThe study population was drawn from patients admitted to six psychiatric hospitals in Germany during a 10-year period (1997–2006). Data from 101 railway suicide cases were compared with a control group of 101 discharged patients matched for age, gender and diagnosis.ResultsPredictors of suicide were change of therapist (OR = 22.86,P= 0.004), suicidal ideation (OR = 7.92,P<0.001), negative or unchanged therapeutic course (OR = 7.73,P<0.001), need of polypharmaceutical treatment (OR = 2.81,P= 0.04) and unemployment (OR = 2.72,P= 0.04). Neither restlessness nor impulsivity predicted in-patient suicide.ConclusionsSuicidal ideation, unfavourable clinical course and the use of multiple psychotropic substances (reflecting the severity of illness) were strong determinants of railway suicides. The most salient finding was the vital impact of a change of therapist. These findings deserve integration into the clinical management of patients with serious mental disease.