Although pathological lying was first described in the medical literature over 100 years ago, it remains a poorly understood concept. Psychiatrists continue to grapple with the full ramifications of the condition, even though interest specifically in pathological lying seems to have waned in recent times. The impact of pathological lying deserves critical attention from forensic psychiatrists because of the implications that untruths have in a legal context. In this article, the authors review the considerable vagueness and confusion that has surrounded this concept and examine the extent to which a person can control lying behavior and the related question of whether pathological liars have responsibility for their actions. While providing a structured framework for considering pathological lying in the forensic context, the authors conclude that further systematic research is needed to resolve the questions raised in this article.