Respiratory tract infections (RTIs) are responsible for the significant part of deaths worldwide. At the special danger of lethal outcome are individuals with higher susceptibility to RTIs, this includes people with any type of immunosuppression, individuals suffering from chronic respiratory tract diseases, persons with some genetic disorders affecting the respiratory organs, children till the age of five and elderly generation. Within the framework of this thesis, the potential role of Raman spectroscopic techniques (RST) for improving prevention and diagnostic strategies of RTIs in such susceptible individuals was assessed, highlighting the need of careful choice of the technique according to the desired clinical task. Firstly, using UV-Resonance Raman spectroscopy (UV-RRS) combined with multivariate analysis, the successful identification of fungal spores especially dangerous to susceptible individuals was demonstrated. Next, utilizing mouse model of aspergillosis, conventional Raman spectroscopy of urine was introduced as an easy tool for screening the RTI and its diagnostic performance was compared to that for other diseases. Lastly, the SERS detection of the metabolite of P. aeruginosa bacterium directly in complex matrixes of saliva and artificial sputum using easily prepared SERS substrates was presented.