Objective: This study aimed to find out the prognostic effect of the prognostic nutritional index (PNI) and controlling nutritional status (CONUT) score for 1-year mortality prediction in older (≥65 years) and younger (<65 years) hospitalized Coronavirus disease-2019 (COVID-19) patients, separately. Materials and Methods: This retrospective and the observational study included 368 patients who were admitted to a single tertiary care university hospital due to COVID-19 disease with positive severe acute respiratory syndrome-coronavirus-2 real-time reverse transcriptase-polymerase chain reaction test. Multivariable Cox regression analyses were performed to predict 1-year mortality prediction for the older and younger groups. Results: Among 368 patients, 112 (30.4%) patients were 65 years and older. There were 45 (12.2%) deaths at the end of the 1-year follow-up. The 1-year mortality rate was higher in the older group (23.2% vs 7.4%). When all patients were analyzed (n=368), PNI [hazard ratio (HR)=0.924, 95% confidence interval (CI)=0.877-0.974, p=0.003] and CONUT (HR=1.423, 95% CI=1.194-1.696, p<0.001) scores were significantly associated with 1-year mortality in multivariable model. When older and younger groups were assessed separately; PNI and CONUT scores failed to estimate 1-year mortality in the older group. On the other hand, the independent estimating capacities of PNI (HR=0.899, 95% CI=0.836-0.966, p=0.004) and CONUT (HR=1.944, 95% CI=1.478-2.557, p<0.001) scores increased when the only younger group was taken into analysis. Conclusion: PNI and CONUT scores as indicators of nutritional and immune status, predicted 1-year mortality in hospitalized COVID-19 patients. However, their prognostic effects in older patients with COVID-19 may be less prominent. Future, large sample studies are needed to provide data about geriatric COVID-19 patients.