PURPOSE: This study aimed to perform a systematic review of the reports on Mycoplasma pneumoniae pneumonia in the last 30 years (1980-2006) to investigate the intervals between outbreaks, change in the peak incidence age, and diagnostic methods. We also aimed to validate the proper diagnostic criteria for M. pneumoniae pneumonia. METHODS: We reviewed 62 original articles on M. pneumoniae pneumonia in Korean children. We analyzed the annual or seasonal variation, study areas, patient age, journal names, and the date of each report. Further, we checked the methods and criteria used for the diagnosis of M. pneumoniae pneumonia. We also confirmed the proper mycoplasma antibody cutoff using the mycoplasma IgM titer as the gold standard. RESULTS: In the last 30 years, epidemic outbreaks of M. pneumoniae pneumonia occurred every 3 years, except in 1993-1994 and 1996-1997. Seasonal variations were also present and were most prevalent in October and November. The number of preschool children, especially those aged 3 years or younger, with M. pneumoniae pneumonia has increased (P<0.05). The mycoplasma antibody titer of 1:640 or greater was appropriate for diagnosing M. pneumoniae pneumonia, with an acceptable sensitivity and specificity of detection. CONCLUSION: We analyzed the results of studies on M. pneumoniae pneumonia in Korean children during the last 30 years. Infection in younger children is increasing, and further research is required to reveal the major cause of the changing epidemics.