“Meth mouth” is the general term for methamphetamine induced rampant caries like “early childhood caries” seen in patients who are addicted to use of illicit drug methamphetamine. Drug abusers usually complaint of “blackened, stained, rotting, crumbling or falling apart” teeth. Oral examination describe a typical pattern of decay involving the facial and cervical areas of both the maxillary and mandibular teeth commonly anterior with less progression to frank coronal involvement. Methamphetamine, a central nervous system stimulant is highly addictive drug of abuse and is used worldwide most commonly because it is cheap and readily available when compared with other illicit drugs. Methamphetamine can be smoked, swallowed, snorted and injected during drug use. The prevalence of specific type of dental caries among users is high along with other oral manifestations. Concentrating on effects of methamphetamine drug abuse on the mouth and dentists role in its diagnosis and management, this case report paper also describes its pharmacology and systemic effects.