The incidence of postoperative morbidity and mortality in hip fracture patients is high and is associated with nutritional deficiencies. This study investigated the predictive value of preoperative prognostic nutritional index (PNI) on postoperative intensive care unit (ICU) requirement and mortality in geriatric hip fracture patients. Geriatric (≥65 years old) hip fracture patients who underwent surgery between January 2021 and September 2023 were evaluated retrospectively. Patients were classified according to the unit followed in the postoperative period (service group and ICU group) and 28-day mortality (mortality group and survivor group). The predictive value of PNI for ICU requirement and mortality and the factors affecting ICU requirement and mortality were investigated. The study included two hundred twenty-two patients, and 66.2% (n=147) were women. In the postoperative period, 47.7% (n=106) of the patients were followed in the ICU and 52.3% (n=116) in the inpatient service. The 28-day mortality of the patients was 6.8% (n=15). PNI was found to be significantly lower in patients followed in the ICU (group ICU) than in those followed in the service (group S) and in patients who died (group mortality) compared to those who lived (group survivor) (p<0.001 and p=0.029, respectively). In multivariate regression analysis, high American Society of Anesthesiologists (ASA) status and low PNI were determined to be independent risk factors for ICU requirement. Acute Physiology and Chronic Health Assessment II score was an independent predictor of mortality. In ROC curve analysis, the cut-off value of PNI in predicting mortality was 32.5, and the area under the curve was 0.660 (95% CI, 0.516-0.803). In geriatric hip fracture patients, preoperative PNI value can be used, like ASA status, in determining postoperative ICU requirements. Nutritional deficiencies are associated with adverse postoperative outcomes in this patient group, and low PNI values (<32.5) help predict in-hospital mortality.