Background <p>In patients with community-acquired pneumonia (CAP), scoring systems are important for determining disease severity and selecting the appropriate unit and antibiotics for treatment. The aim of this study was to determine the 30- and 90-day mortality rates, identify influencing factors, and compare the effectiveness of the PSI, CURB-65, and I-ROAD systems in predicting mortality among patients hospitalized for CAP.</p> Methods <p>We prospectively included adult patients with CAP requiring hospitalization at Hospital between January 2019 and January 2020. Patients were categorized based on the CURB-65, PSI, and I-ROAD systems, and their treatment success as well as 30- and 90-day survival rates were evaluated.</p> Results <p>The study comprised 60 patients with CAP, of whom 40 were male (66.7%). When assessing factors influencing 30-day mortality, the impact of immunosuppression (p:0.004), presence of malignancy (p: 0.003), Apache II score (p:0.014), and steroid use (p:0.004) was found to be significant. Both PSI and CURB-65 had a impact on 30-day mortality (p = 0.005, p = 0.007). Although there was an observed difference in mortality between the I-ROAD groups, its effect on mortality was not statistically significant (p = 0.093). Analyzing 90-day mortality revealed that the PSI and CURB-65 classifications significantly affected mortality (p &lt; 0.001; p = 0.037). Despite a mortality difference among the mild, moderate, and severe I-ROAD groups, the difference was not statistically significant (p = 0.256).</p> Conclusions <p>Both PSI and CURB-65 were significant predictors for both 30-day and 90-day mortality, with PSI exhibiting the highest specificity. I-ROAD did not show statistical significance, although a notable difference was found between the groups.</p>