Oral lichen planus (OLP) is a chronic autoimmune, mucocutaneous disease that affects the oral mucosa as well as the skin, genital mucosa, scalp, and nails. It is one of the most common dermatological diseases presenting in the oral cavity. An immune-mediated pathogenesis is recognized in lichen planus, although the exact etiology is unknown. The disease most commonly affects middle-aged females. It is infrequently found in children, with a prevalence of about 0.03%, and reports of this are scarce in the literature. The erosive and atrophic forms of OLP are less common, yet they are more likely to cause symptoms. OLP is the target of much controversy, especially in relation to its potential for malignancy. Thus, it is important for clinicians to maintain a high index of suspicion for all intraoral lichenoid lesions. Periodic follow-up of all patients with OLP is recommended. In view of the above, the authors highlight a case of gingival erosive lichen planus affecting a 17-year-old adolescent without concomitant cutaneous lesions, with special emphasis on clinical and microscopic characteristics of the condition and management with retinoids and steroid therapy.