Colorectal cancer (CRC) remains an important public health problem in the world. Long noncoding RNA (lncRNA) is an RNA molecular that is longer than 200 nucleotides and cannot be translated into a protein. Recent studies have shown that lncRNAs play important roles in carcinogenesis and cancer metastasis. The aim of this study was to evaluate the expression and biological role of lncRNA maternally expressed gene 3 (MEG3) in colorectal cancer. Quantitative real-time-PCR (qRT-PCR) was performed to investigate the expression of MEG3 in tumor tissues and corresponding nontumor colorectal tissues from 62 patients. The lower expression of MEG3 was remarkably correlated with low histological grade, deep tumor invasion, and advanced tumor node metastasis (TNM) stage. Multivariate analyses revealed that MEG3 expression served as an independent predictor for overall survival. Further experiments revealed that overexpressed MEG3 significantly inhibited CRC cell proliferation both in vitro and in vivo. In conclusion, our study demonstrated that MEG3 is involved in the development and progression of colorectal cancer by regulating cell proliferation and shows that MEG3 may be a potential diagnostic and prognostic target in patients with colorectal cancer.