Purpose: The purpose of this study was to use a systematic review to assess empirical studies on the risk factors for delirium in nursing homes. Methods: Peer-review articles published were identified in CINAHL, PubMed, EBSCOhost, and Medline databases. Studies that met the inclusion criteria were included. Studies were retained for review after meeting strict inclusion criteria. Nine studies were appraised using the criteria in the Quality Assessment Tool. Results: The incidence of delirium ranged from 3.4% to 70.3%. Risk factors were categorized into predisposing and precipitating factors. Nine predisposing (age, cognitive performance scale, dementia, depression, hearing impairment, intravenous catheter during the previous 24 hours, Parkinson’s disease, gender, widowhood) and six precipitating factors (antipsychotics, blood urea nitrogen to creatinine ratio [BUN/CR] >21:1, new drugs, pain, restraints, total protein) were found to be associated with the onset of delirium in nursing homes. Only four (age, dementia, depression, and restraints) of the 15 risk factors were mentioned more than twice. Conclusion: Additional delirium risk factors, such as environmental variables and nurse-staffing factors, should be assessed in nursing homes. This systematic review complements the limitations of individual study results. Based on these results, guidelines should be developed to help prevent delirium in nursing homes.