Deception is ubiquitous in all communication and relationships. It can be conscious, unconscious, or both. It is present in all psychiatric diagnoses as alterations of history, symptom fabrication, symptom enhancement or minimization, and noncompliance with treatment recommendations. We are born better deceivers than we are detectors and untrained intuition may result in very unreliable discrimination. In order to improve our ability to distinguish fact from fiction, the diagnostician must attend to clues in the patient's history and physical and mental status examinations. Laboratory examination, psychological testing, and polygraphy also can be useful adjuncts in detection; however, the first step is always suspicion.