This paper argues that suicide may not always be preventable. This is an argument which is rarely stated. Support for the argument is drawn from historical facts and sociological theory. Mention is made of the clinical problems of dealing with the suicidal patient, and the paper ends with observations of the effects on staff and services of undue criticism. Suicide has been known in all cultures, throughout history, and may be committed in the absence' of mental disorder. Risk factors for suicide are known but they are of limited clinical utility. Prediction and prevention of suicide with certainty is beyond our current abilities. Authorities who examine health professionals and systems in the aftermath of completed suicide doubtless have the best intentions and may respond by making recommendations/criticisms. Information is provided to support the view that undue criticism of mental health professionals and systems in the aftermath of completed suicide may be destructive and work to the disadvantage of patients. Nevertheless, efforts to identify useful markers of suicide risk should continue and high quality psychiatric care should be appropriately available.