Solitary bone cyst is a non-epithelial lined cyst occurring frequently in the long bones and occasionally in the jaw bone. This cyst is most commonly located in mandibular posterior region and incidence rate is higher in the second decade of life. Clinically the cyst is asymptomatic in the majority of cases and is often accidentally discovered during routine radiological examination. Panoramic radiograph is a routine diagnostic radiograph used in the orthodontic patients. The lesion is manifested in Orthopantomograms (OPG) as a well defined unilocular radiolucent lesion with characteristic scalloping of the border when extending between the roots of the teeth. The definite diagnosis of solitary bone cyst is achieved during surgery when an empty bone cavity or cavity filled with a straw colored fluid without epithelial lining is observed. Careful curettage of the lesion favors progressive bone regeneration, offering a good prognosis and an almost negligible relapse rate. A case of incidental finding of solitary bone cyst in the routine radiographic investigation of an orthodontic patient is presented.