Oral lichen planus (OLP) is a relatively common disorder whose cause is still unknown. It occurs mostly on the buccal mucosa, but the gingivae, tongue, floor of the mouth and retromalar pads may also be affected. It rarely occurs on the lips and usually in association with oral lesions. We report a case series of ten patients with a history of isolated swelling of the lower and/or upper lip, erosions and crusting. General medical history, examination of the oral cavity and recording of signs and symptoms were carried out for each patient. Among the six different clinical variants of OLP described by Andreasen, the atrophic-erosive form was the most common in the course of isolated LP of the lip in our series. Five cases presented HCV hepatitis. A complete remission of lesions was observed in eight patients after topical treatment with clobetasol propionate 0.05 percent and tocopherol oil, while partial improvement was noted in those remaining. Isolated LP of the lip is unusual and presents a diagnostic challenge; however an appropriate differential diagnosis is fundamental. Lesions of the lips might represent a more or less precocious phase of oral involvement. Moreover the reasons for the unique localization on the lips need to be explored. Several variables, including age, duration of lesions, concomitance of other diseases, and genetic predisposition may be involved. Isolated LP of the lip is a well-known condition which responds well to topical treatment with corticosteroids. A thorough medical management and active early treatment are necessary to improve symptoms and might also be a relevant prevention strategy from squamous cell carcinoma risk, although data to fully support this statement still need investigation.