Ulcerative colitis (UC) still has no definitive cure since its etiology remains unclear. In recent years, considerable progress has been made with regard to our knowledge of the pathogenesis of UC. Advances in biotechnology have led to the development of biologic therapies which selectively target single key mediators or receptors involved in the pathogenesis of the disease - ie, tumor necrosis factor (TNF)-α, integrin, interleukins 12/23. Biologic therapies caused a revolution in the treatment of UC, providing specific options for patients refractory to conventional treatment. In recent years, antibodies anti-TNFα and anti-integrin have shown efficacy in improving the course and prognosis of ambulatory patients with moderate-to-severe UC. Nevertheless, whether biologics have brought so many benefits also for hospitalized patients with acute severe UC is still debated. Acute severe UC is a potentially life-threatening condition that affects up to 25% of patients during the course of their disease. It requires hospital admission due to the risk of complications and death, and it can necessitate urgent colectomy. Major adverse outcomes of acute severe UC are mortality and colectomy. The aim of this systematic review of the literature was to analyze the impact of biologics, in particular infliximab, on the course and prognosis of acute severe UC. Mortality and colectomy rates were considered as outcome measures.