Colorectal cancer is one of the leading causes of cancer death in both developed and developing nations. It is the third most common type of cancer and the second leading cause of cancer death in the Unites State. The current study included fifty cases of colorectal carcinomas studied histologically, and immunohistochemically for Cathepsin D expression. Cathepsin D expression was observed in 90% of cases in tumor cells and in 92 % of cases in peritumoral stromal cells of colorectal carcinomas. All cases of mucinous and signet ring cell carcinoma and 87.2% of adenocarcinomas showed Cathepsin D positive immunostaining. Statistically significant relationship was detected between Cathepsin D expression in cancer cells and histologic grade but not with lymph node metastasis or stage, however, statistically significant relationship was detected between Cathepsin D expression in peritumoral stromal cells and depth of tumor invasion and , lymph node metastasis. In addition, statistically significant relationship was detected between Cathepsin D immunostaining pattern in tumour cells and histologic grade as in more poorly differentiated tumors, there was a diffuse cytoplasmic staining while in better differentiated tumors there was apical staining pattern reflecting loss of cellular polarization in cancer cells. Therefore, it is suggested that Cathepsin D may be used as a prognostic marker in detection of invasiveness and metastatic potential in colorectal carcinomas and it will be necessary to carry out similar studies on a larger sample size and look for correlations between Cathepsin D expression and survival rate.