Adverse reactions to vaccines vary from mild to fatal. Local reactions are often due to hypersensitivity to the adjuvant substances in the vaccine. This case report aims at illustrating the imaging findings of a fascial injection of the tetanus vaccine. A 14 year-old boy, vaccinated 6 months previously presented with a mass lesion in the left deltoid area. Magnetic resonance imaging and ultrasonographic evaluations were performed and the findings were characteristic for fascial granuloma. The histopathologic examination confirmed the diagnosis. The histopathologic examination confirmed the diagnosis. In our knowledge, this is the first case of granuloma post intrafascial injection of tetanus vaccine which was MRI and ultrasonographic evaluated and histopathologicly confirmed.