Purpose: This study aimed to identify the incidence and related factors of delirium among cancer patients admitted to the general wards of a tertiary hospital. Methods: A retrospective analysis was performed on 9,749 adult cancer patients. Patients who screened positive for delirium were assessed using the Korean version of the Nursing Delirium Screening Scale (NuDESC). Data were analyzed using chi 2 tests, t-tests, and multiple logistic regression. Results: The incidence of delirium was 2.5% (n=243) based on screening results. Significant predictors included older age, longer hospital stays, emergency room admission, 90-day readmission, completion of life-sustaining treatment decisions, surgical department admission, altered consciousness (the strongest predictor), elevated white blood cell and blood urea nitrogen levels, and low albumin levels (p<.050). These 10 factors showed high discriminatory power for delirium (AUC=.91, 95% CI: 0.90 similar to 0.93). Conclusion: The Nu-DESC should be actively utilized in clinical practice for early delirium detection. Nursing interventions must prioritize managing modifiable factors such as nutritional status, infection, and dehydration. Furthermore, case-sharing systems and regular education are essential to enhance nursing expertise and ensure patient safety.