BackgroundDecision analysis is an explicit, quantitative approach to examining difficult decisions about course of action. Its applicability to psychiatry is considered.MethodAn example of how decision analysis could be used in psychiatry is given, criticism of the technique is discussed, and previous attempts to apply it to mental illness problems (from a Medline search from 1966 onwards) are reviewed.ConclusionThe future for decision analysis in psychiatry lies in teaching, audit and research, rather than clinical work.