Pigmentation in the oral mucosa may be divided in physiologic or pathologic lesion. These can be classified into exogenous (induced by drugs, tobacco, amalgam tattoo) and endogenous (caused by systemic disorders, infections, chronic irritation, reactive or neoplastic). For a correct diagnosis several features as duration, colour, localization and distribution must be investigated, and it is necessary to execute a biopsy to exclude neoplastic and traumatic pathologies. The aim of this non systematic review is to report the main features of these lesions based on the recent literature, and to report 3 case reports of pigmented lesions. Two of the three patients are women; two cases in the gingival/alveolar mucosa and one observed in soft palate. They refused to be undergone to the histological examination. The most common pigmented lesions are in the cheek, and amalgam tattoos are the most frequent pigmented lesions reported. The most common types of nevi found are intramucosal (40.4%) and blue nevus (23.4%). The treatment of these lesions is, in the most of cases, surgical excision, also for histological examination.
