Mycoplasma pneumoniae is one of the most common causes of community-acquired pneumonia in children and adults. Correct and rapid laboratory diagnosis of M pneumoniae infections is important to introduce appropriate antibiotic treatment. Diagnosis for M. pneumoniae usually relies on serological tests and/or molecular investigations. Both methods have some advantages but also limitations. This paper presents advantages and disadvantages of microbiological methods used in M. pneumoniae infection an example of case of patient with mycoplasmosis.