This manuscript reviewed the literature on infection by Mycoplasma pneumoniae with emphasis on etiological aspects of childhood community-acquired pneumonias. Bibliographical research was carried out from Pubmed Medline, MDConsult, HighWire, LILACS, and direct research over the past 10 years with the following keywords: Mycoplasma pneumoniae, pneumonia, and childhood. Fifty-four articles were selected. Mycoplasma pneumoniae has a high incidence in childhood. Clinical presentation includes respiratory and extrarespiratory symptoms. Mycoplasma pneumoniae lung infection can be confused with viral or bacterial pneumonia and is unresponsive to beta-lactams. In addition, co-infections have been reported. Mycoplasma pneumoniae infection occurs in all age groups, being less frequent and more severe in children under the age of five. Its incidence as a causal agent is high. Mycoplasma pneumoniae infections constitute 20%-40% of all community-acquired pneumonias; the severity is highly variable, and this condition may lead to severe sequelae. Mycoplasma pneumoniae frequency is underestimated in clinical practice because of the lack of specific features and a diagnosis that needs serology or PCR. Effective management of M. pneumoniae infections can usually be achieved with macrolides. In Brazil, epidemiological studies are needed in order to assess the incidence of this bacterium.