Management of diverticular abscess (DA) is still controversial. Antibiotic therapy is indicated in abscesses ≤ 4 cm, while percutaneous drainage/surgery in abscesses > 4 cm. The study aims to assess the role of antibiotics and surgical treatments in patients affected by DA. We retrospectively analyzed 100 consecutive patients with DA between 2013 and 2020, with a minimum follow-up of 12 months. They were divided into two groups depending on abscess size ≤ or > 4 cm (group 1 and group 2, respectively). All patients were initially treated with intravenous antibiotics. Surgery was considered in patients with generalized peritonitis at admission or after the failure of antibiotic therapy. The primary endpoint was to compare recurrence rates for antibiotics and surgery. The secondary endpoint was to assess the failure rate of each antibiotic regimen resulting in surgery. In group 1, 31 (72.1%) patients were conservatively treated and 12 (27.9%) underwent surgery. In group 2, percentages were respectively 50.9% (29 patients) and 49.1% (28 patients). We observed 4 recurrences in group 1 and 6 in group 2. Recurrence required surgery in 3 patients/group. We administered amoxicillin-clavulanic acid to 74 patients, piperacillin-tazobactam to 14 patients and ciprofloxacin + metronidazole to 12 patients. All patients referred to surgery had been previously treated with amoxicillin-Powered by Editorial Manager®and ProduXion Manager®from Aries Systems Corporation clavulanic acid. No percutaneous drainage was performed in a hundred consecutive patients. Surgical treatment was associated with a lower risk of recurrence in patients with abscess > 4 cm, compared to antibiotics. Amoxicillin-clavulanic acid was associated with a higher therapeutic failure rate than piperacillin-tazobactam/ciprofloxacin + metronidazole.