Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen in cases of atypical pneumonia. Most individuals with Mycoplasma pneumonia run a benign course, with non-specific symptoms of malaise, fever and non-productive cough that usually resolve with no long-term sequelae. Acute lung injury is not commonly seen in Mycoplasma pneumonia. We report a case of acute respiratory distress syndrome cause by M. pneumoniae diagnosed by quantitative real-time polymerase chain reaction (RT-PCR).