Enterocutaneous fistulas (ECFs) remain a feared complication of surgery, particularly in acute care and trauma patients. Despite advances in medical and surgical therapies, ECFs are associated with significant morbidity and mortality; in addition, significant health care resources are consumed in their treatment. Because of the frequency nowadays of open-abdomen and damage-control surgery, of aggressive treatment for abdominal compartment syndrome, and of necrotizing soft tissue infections of the abdominal wall, ECFs are becoming common; so are enteroatmospheric fistulas (EAFs), which represent a new entity where the lumen of the intestine is directly exposed to the outside environment and has no track through subcutaneous or cutaneous tissue. The surgical management of abdominal wall defects, including ECFs and/or EAFs, is often associated with major hernias and other complexities. Careful planning and advanced surgical techniques are required, often involving the use, alone or in combination, of biologic mesh and composite tissue transfer. The treatment of ECFs in patients with large abdominal wall defects is challenging, but with proper techniques, the results can be excellent. Biologic mesh is the mesh of choice in such patients.