The present guidelines aim to provide comprehensive information regarding laboratory diagnosis of Mycoplasma genitalium infections in East European countries. These guidelines are intended primarily for laboratory professionals testing specimens from patients at sexual health care clinics, but may also be useful for community-based screening programmes. Diagnosis of M. genitalium infection is performed exclusively using nucleic acid amplification tests (NAATs), owing to the poor and slow growth of the bacterium in culture. Because no internationally validated and approved commercial NAAT for M. genitalium detection is presently available, it is necessary that laboratories performing M. genitalium diagnostics not only carefully evaluate and validate their in-house PCRs before using them routinely, but also use comprehensive internal controls and take part in external quality assessment programmes. The guidelines were elaborated as a consensus document of the Eastern European Sexual and Reproductive Health (EE SRH) Network, and comprise one element of a series of guidelines aimed at optimizing, standardizing, and providing guidance on quality laboratory testing for reproductive tract infections.