Lamotrigine (LAM), an antiepileptic, with panoply of indications and uses in neurology, is FDA approved, in psychiatry, for bipolar prophylaxis. Apart from this indication, trend of its use in psychiatry is on the rise addressing a multitude of disorders. LAM remains one of only few psychotropic drugs with antiglutamate activity. This might render LAM a potential therapeutic option in treatment-resistant major psychiatric disorders. We reviewed LAM pharmacology and its diverse indications while examining the extant evidence. EMBASE, Ovid MEDLINE, PubMed, Scopus, Web of Science, and Cochrane Database of Systemic Reviews were searched for all relevant studies up to date of June 2016. Sound evidence supports use of LAM for acute bipolar depression and prophylaxis, treatment-resistant schizophrenia, treatment-resistant obsessive-compulsive disorder, posttraumatic stress disorder, depersonalization disorder, and affective dysregulation and behavioral dyscontrol domains of borderline personality disorder. Less compelling evidence is present for use in behavioral and psychological symptoms of dementia and neuropsychiatric sequelae of traumatic brain injury. No evidence supports use in autism spectrum disorder or acute unipolar depression. LAM is an important addition to the psychopharmacological armamentarium. Level of evidence supporting the use of LAM in off-label indications is highly variable, and hence, sound clinical judgment is necessary for its proper use and placement in real-life psychiatric practice and psychopharmacotherapy algorithms.