Furcal perforations may occur during access opening of the pulp chamber or cavity preparation. The perforation can cause an inflammatory reaction in the periodontal ligament. Management of these iatrogenic accidents can pose a significant clinical challenge, mainly when they occur in primary teeth. Current developments in the techniques and materials utilized for root perforation repair have enhanced this procedure's prognosis. Recently, mineral trioxide aggregate (MTA) has been used for several dental purposes. This biocompatible material promotes bone healing and elimination of clinical symptoms. The purpose of this case report was to describe the treatment of a furcal perforation using mineral trioxide aggregate (MTA) in a primary molar tooth. After 20 months, the tooth was asymptomatic. The radiolucent image had disappeared and bone formation at the furcation area had been observed, suggesting healing of the underlying periodontal tissues. Therefore, MTA may be considered an alternative option for the repair of furcal perforation in primary teeth, prolonging the longevity of these dental elements.