The purpose of this paper is to provide psychiatrists with practical advice on how to detect malingered mental illness. Various types of malingering are defined and the five major purposes of malingering are specified. The research literature on malingering is reviewed. Clinicians must be thoroughly grounded in the phenomenology of true mental disease to detect malingering. Detailed information about hallucinations is reviewed so that faked hallucinations that do not follow typical patterns can be more easily identified. Strategies for approaching persons suspected of malingering are suggested. Features of malingered mutism, mania, depression and mental retardation are described. The differential diagnosis of malingering, post-traumatic stress disorder, conversion disorder, and post-concussion syndromes after trauma is discussed. Clues to malingered psychoses and post-traumatic stress disorders are delineated. Finally, specific indicators of malingered insanity defenses are identified.