Background: intestinal ischemia is a potentially catastrophic disease. Its mortality has been associated with the extent of bowel necrosis and there is little information about predictive factors once the necrosis has been stablished. The aim of this study is to explore the possible association between preoperative serum lactate levels and the extent of bowel ischemia and mortality. Methods: An observational study of prognosis or prediction, in a retrospective cohort, was performed, in patients with acute intestinal ischemia (AII), confirmed by laparotomy, in Méderi – Hospital Universitario Mayor between 2012 and 2018. Results: 74 cases were included. 44 males (59.5%) y 30 females (40,5%). The average age was 73,5 ± 10.8 years with a range between 47 and 90 years. All patients presented abdominal pain. Occlusive –embolic– was the origin of mesenteric ischemia in 75,7% (56 cases) and non-occlusive mesenteric ischemia –NOMI– in 24.3% (18 cases). Mean lactate was 6,24 mmol/l (SD 4,00). There was a lineal moderate association between serum lactate and the extent of bowel ischemia. (r=0.205, p=0.04). Serum lactate levels were significantly higher in patients with deadly outcome (p<0.001) and had a mortality prediction area of 80,8% with lactate levels of 3,5 mmol/l, 83% sensitivity and 71,4% specificity. Conclusions: the elevation of serum lactate is directly associated with the extent of bowel ischemia and the mortality from the disease. This results can influence clinical and surgical decision making.