Background Hospital Elder Life Program (HELP) provides protocols based on factors for reducing delirium. Due to the lack of geriatric wards and aged care teams in Iran, it seems that some of the original HELP interventions need to be modified through a trial study. Hence, this study was conducted to determine whether the Iranian modified HELP could reduce delirium in geriatric hospitalized patients. Methods This double-blind randomized controlled trial was designed and conducted in a hospital at Kashan University of Medical Sciences in Iran. A total of 195 hospitalized patients aged ≥70 years, were 84 in the Intervention Group (IG) and 111 in the Control Group (CG). After assessing delirium risk factors, participants in the IG group received interventions based on the cognitive, vision/hearing, sleep, mobility, feeding, and hydration protocols by nursing students and the CG group received routine care. Delirium incidence was assessed by the Confusion Assessment Method. Delirium incidence, cognitive and functional abilities, frailty, fall, and length of stay were outcomes. Results The mean age of the patients was 78.53(Standard Deviation = 5.87) years. Delirium incidence was higher in the CG comparing to IG (14.71% vs 3.66%).Significant reduction observed in risk incidence of delirium because of interventions [Odds Ratio:0.124, Confidence Interval: 0.03–0.48]. Conclusion The modified HELP effectively reduced delirium rates in geriatric hospitalized patients. Trial registration This study was registered at the Iranian Registry of Clinical Trials IRCT20180910040995N1.