Summary Background Right-sided colonic diverticulitis (RD) is much rarer than left-sided (LD) and controversies concerning the most appropriate treatment remain unsolved. Most Western centers treat RD with inpatient management independently of the severity of the disease. The aim of this study is to compare RD and LD patients who were treated as inpatients in order to define the RD patients who could benefit from outpatient management. Methods We performed a retrospective comparative study in which all acute diverticulitis patients admitted to our hospital from June 2015 to December 2019 were included. Clinical features, radiological findings, type of treatment, complications rate, and relapse time were analyzed in both groups. Results From a total of 239 patients, 24 patients with RD and 94 patients with LD were included. American Society of Anesthesiologists (ASA) classification was significantly lower in RD ( p  = 0.005). The presence of pneumoperitoneum in CT scan was significantly higher in LD ( p  = 0.001) and no RD patient required any kind of surgical intervention including percutaneous drainage. In contrast, 23.4% of LD patients needed a surgical procedure ( p  = 0.001). Third-line antibiotics of were only prescribed in left diverticulitis ( p  = 0.003). Length of hospital stay was significantly shorter in RD patients ( p  = 0.001). Conclusion Patients with right diverticulitis had fewer perforations, required lower-spectrum antibiotics, and did not require any surgical treatment, with a shorter length of hospital stay. Given these results, we consider that mild right diverticulitis could benefit from an outpatient treatment following similar recommendations to those followed for mild LD patients. This is one of the largest series in Western literature and the only one that compares clinical features, complication rates, and type of treatment between right and left diverticulitis. Outpatient management in RD is a feasible option which is not only safe but can also reduce costs.