Ranula is a mucosal cyst that occurs in the mouth floor. This is a pseudo cyst caused by mucous retention within the tissue due to the rupture of catheter in the salivary gland. Ranula occurs mainly in a unilateral form and is characterized by painless bluish transparent swelling, with a increasing mass size. If the size is large, it can cause discomfort during swallowing, pronounciation, and mastication, but external swelling and infection is rare. Treatments include observation for spontaneous resolution, simple incision and drainage, marsupialization and excision. Marsupialization done by removing parts of the cyst wall and connecting it to the oral mucosa. It is a conservative procedure and recommended for children. It has advantages such as maintaining outline of oral tissue and less risk of damaging anatomic structure. Recurrence is common, mostly occurring within 4 months after surgery. This case is about a eight-year-old girl with ranula on the right mouth floor. This patient was treated with marsupialization that is one of treatment for ranula, and recurrence was not observed