ABSTRACT. We investigated the associations between Beclin-1 and microRNA-30a (miR-30a) expression and the severity and treatment response in colorectal cancer (CRC). Our sample size consisted of 139 CRC patients who were treated with surgery alone. Immunohistochemistry was used to investigate the expression and prognostic significance of Beclin-1 in CRC, while the weak expression of Beclin-1 in normal tissue was used as the basis for assessing tumors (control group). Real-time reverse transcription-polymerase chain reaction quantified miR-30a levels. The expression levels of Beclin-1 and miR-30a were associated with clinical variables and prognoses. Beclin-1 was expressed more highly in CRC tissues than in controls. This expression was related to gender (P = 0.023), histological grade (P = 0.006), M stage (P = 0.004), tumor node metastasis stage (P = 0.020), vascular invasion, and nodal involvement. Patients with higher Beclin-1 expression levels had higher survival rates (P = 0.08) than patients with lower Beclin-1 expression levels. Beclin-1 was a prognostic indicator (P < 0.05) in a multivariate analysis. Beclin-1 was overexpressed in CRC tissues and was correlated with lower levels of miR-30a (P < 0.05, r = -0. 4189). In conclusion, Beclin-1 was a good prognostic indicator in CRC and was correlated with survival rate. Beclin-1 is important in the growth and metastasis of CRC. Apoptosis in CRC might be due to the increased autophagy induced by decreased levels of miR-30a.