Abstract An epidermoid cyst is a benign cyst that can occur in any part of the body. The most common age group for this cyst is 20–40 years. It's extremely rare in oral cavity accounting for only 1.6%. The cyst develops from the ectodermal tissue. It represents the most common cutaneous cysts. A 6 years old female patient presented with a complaint of swelling in the floor of the mouth. It measured 4 × 5 cm in size. Surgical excision with primary closure was performed. We present this case because of its rare location, mistaken for other entities, like a ranula and its occurrence at an early age. After excision, an oval-shaped mass of 4 × 5 cm has been described in this case. The histopathological report confirms the diagnosis of epidermoid cyst. The epidermoid cyst commonly occurs in middle-aged adult group, especially over the face, scalp & trunk area. Surgical excision is the treatment of choice in such case. Epidermoid cyst of the oral cavity is an uncommon entity. Although it's common in middle-aged adult but sometimes it may occur in pediatrics age group.