Growth differentiation factor 11 (GDF11), a member of the transforming growth factor-beta superfamily and bone morphogenetic protein (BMP) subfamily, plays a role in regulation of development and differentiation. Although some members of BMP subfamily have been reported to correlate with cancer, the significance of GDF11 has not been studied in a clinical oncology setting. The current study explored the clinicopathological significance of GDF11 expression in colorectal cancer. Quantitative real-time reverse transcription-PCR in colorectal cancer specimens obtained from 130 patients showed that GDF11 mRNA expression in cancer tissue was significantly higher than in normal tissue (p=0.001). Tumors were classified as high GDF11 expression (n=65) or low GDF11 expression (n=65). Patients whose tumors had high GDF11 expression showed a high frequency of lymph node metastasis (p=0.049) and had more cancer-related deaths (p=0.040). Furthermore, the patients with high GDF11 expression had significantly poorer overall survival than those with low expression (p=0.0334). Although multivariate analysis showed that GDF11 was not an independent prognostic factor, these findings suggest that GDF11 may be a novel diagnostic and prognostic biomarker in patients with colorectal cancer.