Pseudologia fantastica, also known as mythomania, or pathological lying, is a psychiatric phenomenon that is a mixture of fact and fiction involving fantasized events and self aggrandizing personal roles. It has been recognized in the field for over a century. In this case report we discuss three different cases, two of them presented in the acute inpatient setting and one outpatient setting. All three presented with the common theme of extensive and 'pathological lying' in a manner that was notably very destructive to them and posing significant challenges to the treatment team. In an attempt to shed light into some of the clinical and legal/forensic challenges it creates when faced in the clinical settings, we also raise the need for a better definition and classification of this symptom in the DSM.