To investigate the relative expression level and clinical significance of LINC00475 in serum of patients with multiple myeloma (MM). The expression of LINC00475 in serum of 108 MM patients and five MM cell lines including RPMI 8226, NCI-H929, U266, OPM2 and CAG were detected by real-time fluorescence quantitative PCR. The diagnostic value of LINC00475 in MM was evaluated by receiver operating characteristic (ROC) curve analysis. The correlation of LINC00475 with patients' characteristics was analyzed. Compared with control groups, the expression of LINC00475 was up-regulated in serum of MM patients and MM cell lines (all P < 0.05). ROC curve analysis showed that the optimal cut-off value of LINC00475 was 262.4, the area under curve (AUC) was 0.924(95%CI : 0.884-0.964), and sensitivity and specificity was 83.3% and 91.7%, respectively, which indicated that LINC00475 had good evaluation value in MM patients. Compared with low-LINC00475 expression group, patients in high-LINC00475 expression group had higher levels of β2microglobulin (β2-MG) and Cystatin C (Cys-C) but lower albumin (ALB) (all P < 0.05). Compared with MM patients with International Staging System (ISS) stage I, the expression level of LINC00475 was significantly higher in patients with stage II and III (both P < 0.05). LINC00475 is helpful to distinguish MM patients from healthy adults, which is correlated with the prognostic indicators such as β2-MG, ALB, and ISS stage.