Traumatic neuromas are rare benign tumors that are common after trauma or surgery and are usually accompanied by obvious symptoms of pain. Most reports show neuromas in the face, neck, and limbs, and the traumatic neuroma of the medial plantar nerve has rarely been reported. We encountered a traumatic neuroma of the medial plantar nerve after a deep laceration mimicking a foreign body granuloma. A small mass lesion was found around plantar aponeurosis with heterogeneous high signal intensity in the T2 fat suppression view and slightly enhanced intensity in the magnetic resonance imaging that suggested a foreign body granuloma. The lesion was diagnosed pathologically as a traumatic neuroma. A satisfactory clinical result was obtained after excision of the traumatic neuroma and burial of the proximal and distal stumps to the adjacent muscle at the secondary operation.