Odontogenic keratocysts (OKCs) are one of the most frequently encountered cystic diseases of the jaw in clinical practice. Although OKC has been reported as a manifestation of nevoid basal cell carcinoma syndrome (Gorlin syndrome) in many pediatric patients, there have been few reports of OKC occurring in isolation. Herein, we report the case of a relatively large OKC in the mandibular body of a 7‐year‐old girl who was treated conservatively using cystectomy and open wound surgery, and the permanent teeth were unaffected. Regular check‐ups, including radiographic examinations, starting in childhood may contribute to the early detection of lesions in the maxillofacial region.