PURPOSE: The purpose of this study is to evaluate the value of nonoperative treatment for right-sided colonic diverticulitis. METHODS: One hundred fifty-eight patients with right-sided colonic diverticulitis were evaluated. Clinical history, physical and radiologic findings, and treatments were reviewed retrospectively. Also, additional episodes and treatment modalities were checked. RESULTS: Our patients were classified according to treatment modality; 135 patients (85.4%) underwent conservative treatment, including antibiotics and bowel rest, and 23 patients (14.6%) underwent surgery. The mean follow-up length was 37.3 months, and 17 patients (17.5%) underwent recurrent right-sided colonic diverticulitis. Based on treatment modality, including surgery and antibiotics, no significant differences in the clinical features and the recurrence rates were noted between the two groups. CONCLUSION: Conservative management with bowel rest and antibiotics could be considered as a safe and effective option for treating right-sided colonic diverticulitis. This treatment option for right-sided colonic diverticulitis, even if the disease is complicated, may be the treatment of choice.