Mycoplasma pneumoniae is a bacterium that lacks a cell wall. It produces infections all It produces infections world-wide, in epidemic outbreaks every 4-7 years, or endemically. Its clinical manifestations occur mostly in the respiratory tract and it is a common cause of atypical pneumonia. The treatment is with macrolides, tetracyclines or fluoroquinolones. Since 2000, an increase in resistance to macrolides has been detected worldwide, being more frequent in Asia. In Europe the frequency of resistance ranges between 1% and 25%, depending on the country. Molecular techniques and serology techniques provides very high sensitivity in diagnostic confirmation, being very useful for detecting and controlling M. pneumoniae outbreaks. The detection of resistance to macrolides requires a sequencing technique.