Introduction: Since delirium is a major complication that can arise after a patient with a hip fracture has been hospitalized, it is considered to be one of the most common geriatric conditions. Therefore, its prevention and early detection are essential for reducing both the length of the patient’s stay in the hospital and complications during the hospitalization process. Objective: To identify and analyze the predictors for developing delirium in octogenarians who were admitted to hospital for a hip fracture. Methodology: A prospective study conducted with a sample of 287 patients aged 80 years and older (mean age 87.2 ± 3.2 years; 215 women, 72 men), recruited from the Trauma Unit of the University Hospital of León (Spain). Further, 71.1% of the patients lived in a family member’s home, while the other 28.9% lived in a nursing home. After observing each patient’s interactions with their doctor in a clinical setting, the data for this study were obtained by reviewing the selected patients’ charts. The variables analyzed were sociodemographic information (age, sex, and place of residence), medical information (type of hip break and surgical intervention), cognitive impairment (MMSE score), functional level (Barthel Index score), and clinical information (pharmacological, comorbidities, complications, and the diagnosis and assessment of the severity of delirium in a patient). The univariate and multivariate logistic regression analysis showed a significant relationship between acute confusional state and the following variables: anemia, American Society of Anesthesiologists (ASA) III and IV patients, state of cognitive frailty and functional level, a urinary tract infection, changes in the visual field, renal arterial occlusion, and the type and dosage of drugs administered (this variable was identified in the multivariate model). The inverse relationship between anemia and acute confusional state is surprising. Conclusion: This research shows that clinical observation of acute confusional state is necessary but not sufficient for addressing this condition early and adequately in older adults who have been hospitalized for a hip fracture.