Background: Nasal septoplasty is a common surgical procedure, but a significant number of patients report equal, or some even worsened, symptom load postoperatively. Rhinologists struggle to find objective tests that adequately reflects disease burden. This study aimed to evaluate the correlation between the PNIF measurement of the most obstructed side with patient reported outcomes. Methods: Bilateral and unilateral PNIF measurements were performed before and after topical decongestion in 528 patients scheduled for surgery due to nasal obstruction. Subjective outcomes were measured using Nasal Obstruction VAS and SNOT-22 with subdomains. Correlations between subjective and objective measurements were calculated and further explored using multivariate regression analyses. Results: Significant negative correlations between PNIF and patient reported outcomes were found. Both bilateral and minimal unilateral PNIF correlations with NO-VAS were equal and stronger than correlations with SNOT-22 including subdomains concerning problems with nasal obstruction. Minimal unilateral PNIF did not show statistically significant gender difference. Topical decongestion decreased statistical correlations. Conclusions: The minimal unilateral PNIF shows a statistically significant but weak negative correlation with preoperative patient reported nasal obstruction, and values do not differ between genders. Clinical evaluation of patients presenting complaints of nasal obstruction could be supported by minimal unilateral PNIF.