A great many circular RNAs (circRNAs) exist in different types of mammalian cells. Previous studies have verified that a low level of hsa_circ_0002320 is present in gastric cancer and that it might represent a good prognostic indicator. However, its value in colorectal cancer (CRC) is unclear. The aim of this research was to explore the value of hsa_circ_0002320 as a potential diagnostic biomarker for CRC prognosis. Plasma samples, CRC tissues, and adjacent normal tissues were obtained from 50 patients with CRC, before any treatment, and 100 plasma samples were acquired from healthy individuals. Hsa_circ_0002320 levels in these samples were analyzed by reverse transcription-quantitative polymerase chain reaction. Correlations between hsa_circ_0002320, clinicopathological characteristics, and overall survival (OS) of CRC patients were also investigated. Receiver-operating characteristic (ROC) curve analysis was used to assess the value of hsa_circ_0002320 for CRC diagnosis. Finally, a bioinformatics analysis was performed to verify the effect of hsa_circ_0002320 on CRC prognosis. Expression levels of hsa_circ_0002320 were significantly decreased in CRC plasma (P< .05). The expression level of hsa_circ_0002320 was significantly correlated with OS time (P < .05). Higher hsa_circ_0002320 reflected significantly greater OS; the HR of high hsa_circ_0002320 was 0.161 (95% CI, 0.066-0.393;P = .000). The area under the ROC curve of hsa_circ_0002320 in CRC was 0.823, which was higher than for the carcinoembryogenic antigen (area under the curve = 0.764). Kaplan-Meier analysis showed that CRC patients with low expression of hsa_circ_0002320 exhibited poorer OS times than those with high expression. Hsa_circ_0002320 could be a novel, noninvasive diagnostic blood biomarker for CRC prognosis.