Complicated intra-abdominal infections such as acute appendicitis and complicated diverticulitis represent both diagnostic and therapeutic challenges. Both diseases, although different in many ways, are caused by the obstruction of a blind pouch leading to inflammation, abscesses, and perforation of surrounding tissues. For many decades, acute appendicitis was managed through a conventional surgical incision in the right iliac fossa. As for other diseases, there is a significant tendency to propose less invasive treatments. For many teams, laparoscopy, which leads to less postoperative pain, a shorter hospital stay, and a quicker recovery, represents the standard of care for appendectomy. For selected cases, a medical approach can be proposed with satisfactory outcomes. Additionally, the management of complicated diverticulitis is also quickly moving towards less invasive procedures than the deleterious ‘3-phase surgery', which is Hartmann's procedure, followed by reversal protected with a stoma, and finally stoma closure. Benefiting from the evolution of antimicrobial therapy and interventional radiology, many complicated cases classified as Hinchey stage I and Hinchey stage II complicated diverticulitis are now treated medically. CT images allow the identification of patients requiring radiological drainage of localized abscesses or collections over 5 cm in size. Patients with Hinchey stage III sigmoiditis may benefit from an initial laparoscopic exploration allowing, in some cases, a conservative nonresective approach that will prevent laparotomy and stoma. Major resection leading to temporary or definitive stoma is usually indicated for stage IV complications and is required only in exceptional cases. Although a surgical intervention can be the definitive treatment for complicated intra-abdominal infections, multidisciplinary management including radiology, medical treatment, and laparoscopic surgery may limit the severe consequences of an acute surgical approach in patients suffering from complicated appendicitis and diverticulitis. Today, the ultimate goal of acutely infected abdomen management is to reduce hospital stay, disability, and numerous operations for these patients.