Mesenchymal hamartoma of the chest wall is an extremely rare, benign chondro-osseous chest wall tumor which originates from one or more ribs, in newborns or infants. It usually appears as a solitary lesion but more rarely can be multifocal and bilateral. Sometimes it may mimic chest wall malignant tumors because of its destructive radiological nature. Herein, we aim to present the imaging characteristics of a 4-day-old boy with multifocal mesenchymal hamartoma of the chest wall. Keywords : mesenchymal hamartoma, chest wall tumor, neonate, computed tomography, magnetic resonance imaging