Currently, there is no unified algorithm of a laboratory examination of patients with sexually transmitted infections (STIs). The applicability of new high-performance (biomolecular) methods, such as the NASBA transcriptional amplification reaction and the polymerase chain reaction (PCR), in laboratory diagnosis requires a detailed clarification. The aim of the study was to develop an algorithm of a laboratory examination for detection of N. gonorrhoeae, C. trachomatis, T. vaginalis, and M. genitalium using PCR and NASBA. Material and Methods. The AmpliSens N.gonorrhoeae/C.trachomatis/M.genitalium/T.vaginalis — MULTIPRAYM-FL kits were used for PCR. The AmpliSens Neisseria gonorrhoeae — RIBOTEST, AmpliSens Chlamydia trachomatis — RIBOTEST, AmpliSens Trichomonas vaginalis — RIBOTEST and AmpliSens Mycoplasma genitalium — RIBOTEST NASBA-based kits were used to determine RNA. For developing a laboratory examination algorithm, evaluation of diagnostic characteristics of the used PCR and NASBA-based kits in comparison with other diagnostic (bacterioscopic, serological, bacteriological) methods was performed. Results. A PCR and NASBA-based algorithm of a laboratory examination was proposed for diagnosing gonococcal, chlamydial, trichomonal and Mycoplasma genitalium infections. Based on this algorithm, the trichomonal infection in 32 patients with negative bacterioscopy and the gonococcal infection in 26 patients were confirmed. In addition, the trichimonal infection diagnosis was excluded in three patients with positive bacterioscopy. Conclusion. Practical application of the PCR and NASBA-based algorithm for diagnosis of N. gonorrhoeae, C. trachomatis, M. genitalium and T. vaginalis infections will improve the quality of care for STI patients and standardize the use of various diagnostic methods in clinical practice.