It has been determined that long noncoding RNAs (lncRNAs) are identified as a potential regulatory factor in multiple tumors as well as multiple myeloma (MM). However, the role of colorectal neoplasia differentially expressed (CRNDE) in the pathogenesis of MM remains unclear. In this study, we found that the CRNDE expression level, in MM samples and cell lines, is higher than that in the control detected by real-time qPCR, which is also closely related to tumor progression and poor survival in MM patients. Knockdown of CRNDE significantly inhibits the proliferative vitality of MM cells (U266 and RPMI-8226), induces cell cycle arrest in the G0/G1 phase, and promotes apoptosis. After being transfected with siRNA, miR-451 expression observably increases. Bioinformatics analysis and luciferase assay reveal the interaction by complementary bonding between CRNDE and miR-451. Pearson's correlation shows that CRNDE is negatively correlated to miR-451 expression in human MM samples. Subsequently, miR-451 inhibitor rescues the inhibited tumorigenesis induced by CRNDE knockdown. Our study illustrates that lncRNA CRNDE induces the proliferation and antiapoptosis capability of MM by acting as a ceRNA or molecular sponge via negatively targeting miR-451, which could act as a novel diagnostic marker and therapeutic target for MM.