Aim: Our aim is to investigate the factors affecting on postoperative morbidity and mortality in patients who underwent emergency surgery for acute intestinal obstruction due to colorectal cancer. Material and Method: Forty-three patients who was operated because of acute obstructing colorectal cancer without perforation were retrospectively evaluated. Logistic regression analysis was used to identify the main prognostic factors affecting postoperative morbidity and mortality. Results: Postoperative morbidity was developed in 16 (37.6%) patients while mortality was seen in 8 (18.6%) patients during the postoperative period. In univariate analysis, age above 65 years (p= 0.034), accompanying systemic disease (p= 0.035), advanced tumor stage (p= 0.040), and high ASA score (p= 0.000) were found to be associated with the development of postoperative morbidity. On the other hand, age above 65 years (p= 0.023), accompanying systemic disease (p= 0.014), high ASA score (p= 0.010), and presence of distant metastasis (p= 0.012) were identified as the risk factors related to postoperative mortality. After logistic regression analysis, age above 65 years (p= 0.023) and high ASA score (p= 0.000) were determined as the prognostic factors of postoperative morbidity, while high ASA score (p= 0.005) and presence of distant metastasis (p= 0.000) were found to be the independent prognostic factors of postoperative mortality. Discussion: Older age and the presence of accompanying systemic diseases increase the postoperative morbidity and mortality in patients who underwent emergency surgery for obstructing colorectal cancer. ASA score, as a strong prognostic factor for both morbidity and mortality, can be easily used in preoperative risk stratification and surgical planning.