Background Elderly patients admitted because of acute cholecystitis are usually not operated during their initial admission and receive conservative treatment. To help formulate a new admission policy regarding elderly patients with acute cholecystitis we compared the demographic and clinical characteristics and outcome of patients > 65 with acute cholecystitis admitted to medical or surgical wards. Methods This retrospective study included all patients > 65 years admitted for acute cholecystitis between January, 2009 and September, 2016. Data were retrieved from the electronic health records. Results A total of 187 patients were detected, 54 (29%) in medical departments and 133 (71%) in surgical wards. The mean age (±SD) was 80 ± 7.5 and was higher among those in medical than surgical wards (84 ± 7 versus 79 ± 7, p <  0.05). Patients hospitalized in medical departments had more comorbidity, disability and mental impairment. However, there was no difference in mortality between the two groups, 1 (2%) and 6 (4%) respectively. Independent predictors for hospitalization in medical departments were chronic obstructive pulmonary disease (OR = 9.8, 95% C. I 1.6–59) and the Norton Scale score (NSS)(OR = 0.7, 95% C. I 0.7–0.8). Impaired mental condition was the only predictor for hospitalization > 1 week. The strongest predictor for having cholecystostomy was admission to the surgical department (OR = 14.7, 95% C. I 3.9–56.7). Linear regression showed a negative correlation between NSS and length of hospitalization (LOH; Beta = − 0.5). Conclusion Elderly patients with acute cholecystitis who require conservative management, especially those with severe functional and mental impairment can be safely hospitalized in medical departments. Outcome was not inferior in terms of mortality and LOH. These results have practical policy implications for the placement of elderly patients with acute cholecystitis in medical rather than surgical departments.