Mycoplasma pneumoniae is a leading cause of a community-acquired respiratory illness occurring in children with manifestations occurring throughout the year but peaking in summer and early fall. Predominantly affecting school-aged children, the infection presents as pneumonia, featuring fever, cough, dyspnea, and sore throat. Extrapulmonary manifestations such as Stevens-Johnson have been rarely associated with mycoplasma pneumoniae infection presenting with ocular, oral, and genital involvement. We report a case of a 7-year-11-month-old girl presenting with a 9-day fever history and 3-day bilateral conjunctivitis, aphthous stomatitis, and mucositis. After several investigations, a diagnosis was made and results showed a mycoplasma pneumoniae infection complicated with Steven-Johnson syndrome.