Purpose Acute diverticulitis is a common condition with increasing prevalence worldwide,however optimal management of this condition remains unclear. This study aimed to determine current practice and short-term outcomes globally. Methodology A prospective, international cohort study of consecutive patients presenting with acute diverticulitis to secondary care units from 10/2020 - 08/2021 was undertaken. Countries were stratified into high or low middle income groups as per UN’s Human Development Index. The primary outcome of interest was the geographical variation in presentation and treatment. The secondary outcome was treatment success at 30 days. Results 6285 patients were recruited from 248 hospitals across 48 countries. 2798 patients presented with uncomplicated disease, of whom 30.3% were treated in an ambulatory manner. Overall, antibiotic use was high in all regions (92.7% to 99.4%). Patients in LMIC’s were less likely to undergo CT (87.8% vs 99.2%, p<0.001) and more likely to undergo emergency surgery (25.4% vs 13.5%, p<0.001). Surgical resection varied between regions (8.8% to 42.8%). The overall 30-day surgical complication rate was 39.7%, with an overall 30-day mortality of 2.8%. Treatment failure was higher in patients with complicated disease (4.5% vs 1.0%) and in LMIC units (6.2% vs 2.1%). Conclusion DAMASCUS study reveals significant variation in the management and outcomes of patients presenting with acute diverticulitis. Antibiotic use was alarmingly high. Patients presenting in LMIC units were more likely to be sicker, requiring emergency surgery, and this was associated with a higher 30-day mortality rate.