A seven-year-old boy admitted with the complaints of fever, weakness in legs, sensory loss in lower limb, and difficulty in voiding lasting for two weeks. His initial symptoms also included cough and fever. His spinal magnetic resonance imaging scan demonstrated acute transverse myelitis, and Mycoplasma pneumoniae-specific IgM and IgG antibodies were found to be positive in cerebrospinal fluid (CSF) and serum samples. He was treated with a single high-dose intravenous immunoglobulin (2 g/kg/dose) and clarithromycin. Mycoplasma pneumoniae is a frequent cause of upper and lower respiratory tract infections in children. Central nervous system (CNS) manifestations are among the most frequent extrapulmonary complications during the course of the disease. They occur most frequently in children, usually within three weeks after the onset of respiratory illness, with an incidence of approximately 1 in 1,000 patients. In this report, we present a seven-year-old boy with transverse myelitis during the course of Mycoplasma pneumoniae infection with serological confirmation both in serum and CSF samples.