Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen empirically covered in pulmonary infections. Limited studies evaluate the relationship between MRSA PCR nasal swab assays and clinically diagnosed ventilator-associated pneumonia (VAP), lung abscess, and empyema. This retrospective, single-center study included 161 patients, which aimed to validate the clinical utility of MRSA PCR nasal swabs in VAP, lung abscess, and empyema through sensitivity, specificity, positive predictive value (PPV), and negative predicative value (NPV) analysis. VAP had a 100% sensitivity, 89% specificity, 67% PPV, 100% NPV. Lung abscess had a 0% sensitivity, 90% specificity, 0% PPV, 90% NPV. Empyema had a 80% sensitivity, 84% specificity, 42% PPV, and 97% NPV. The study results demonstrate that the MRSA PCR nasal swab assay has the potential to be a vital tool in de-escalating antimicrobial therapy in VAP, lung abscess, and empyema.