Oral lichen planus (OLP) is classified as a potential malignant disorder, and epidermal growth factor (EGF) may play a key role in cancer development. The aim of this study was to compare serum and saliva EGF among patients with OLP and oral squamous cell carcinoma (OSCC). A cross-sectional study was performed on 27 patients with OLP (10 reticular and 17 atrophic-erosive forms), 27 patients with OSCC and 27 healthy control group. The study was conducted at the Cancer Department, Clinic of Oral Medicine, Tehran University of Medical Sciences. The serum and saliva EGF were assayed by ELISA method. Statistical analysis of ANOVA was used. The mean serum EGF in OLP and OSCC patients was significantly lower compared to healthy control group (P < 0.05), but no significant difference was observed between OLP and OSCC patients. There was no significant difference in mean salivary EGF among groups. As serum EGF levels appear to be statistically similar in OLP and OSCC, it seems that EGF might play a role in the pathogenesis of OLP and its cancerization.