Objective To evaluate the value of multislice spiral CT (MSCT) in the differentiation between mucinous and non-mucinous colorectal carcinoma. Methods MSCT imaging data of 69 patients with mucinous colorectal carcinoma and 85 patients with nonmucinous colorectal carcinoma confirmed by pathology were analyzed retrospectively. MSCT findings were compared between the two groups with regard to the bowel involvement patterns, patterns of contrast enhancement, secondary bowel obstruction, intratumoral calcification, pericolic fat infiltration, and tumor extension to adjacent organs. Results Compared with nonmucinous carcinoma, mucinous carcinoma showed more severe bowel-wall thickening (2.52±1.14cm vs 1.91±0.96cm) (P=0.003) .Heterogeneous enhancement was more common in mucinous than nonmucinous carcinoma (84.1% vs 51.8%) (P=0.001). Mucinous carcinoma showed more areas with low density (P=0.001) and more eccentric degree(P=0.027),and its solid portion showed less enhancement than that of nonmucinous carcinoma (P=0.001), and the presence of intratumoral calcification were more frequent in mucinous carcinoma (P=0.001). Heterogeneous enhancement showed the highest sensitivity (84.1%) but moderate specificity (58.4%) in diagnosing mucinous carcinoma. Tumors with four or more CT findings with a statistically significant difference were mostly mucinous carcinoma, and the specificity was 90.5%. Conclusion MSCT can be used as an effective method for the differential diagnosis between mucinous and nonmucinous colorectal carcinoma.