The objective of this investigation was to assess the prevalence of oral lichen planus (OLP) in Moroccan patients infected with hepatitis C virus (HCV) from the Hepatology service of Ibn Sina University hospital of Rabat. The study group consisted of 149 patients with HCV infection. All patients with clinical features of OLP were submitted to the service of oral surgery for confirmation. Among the 149 HCV-infected patients of the study group, 35 patients had OLP which represents a prevalence of 23.5%. Two out of these 35 patients with OLP-HCV association had cutaneous lichen planus (CLP) as well. Our findings indicate that there is a significant association between OLP and HCV infection especially for reticular and erosive types of OLP.