The aim of this study was to investigate the gene expression of programmed cell death 5 (pdcd5) in plasma and bone marrow cells from patients with multiple myeloma (MM). Enzyme liked immunosorbent assay (ELISA) and real-time quantitative reverse transcription polymerase chain reaction (RQ-RT-PCR) were used to examine pdcd5 gene expression in plasma and marrow cells in 45 MM patients and 20 normal controls. The results showed that serum levels of PDCD5 protein in 45 MM patients were lower significantly compared with the normal controls and 20 responsive patients after chemotherapy, their plasma levels were (16.91 +/- 0.28) ng/ml, (19.11 +/- 0.29) ng/ml and (17.94 +/- 0.154) ng/ml respectively (p < 0.05). The pdcd5 gene expression levels detected by RQ-RT-PCR in 45 MM patients were lower significantly compared with the normal controls, their pdcd5 gene expression levels were 0.64 +/- 0.47 and 1.28 +/- 1.21 respectively (p < 0.05). It is concluded that the PDCD5 protein expression levels are low in patients with MM. These findings suggest that abnormal expression of pdcd5 may be involved in the pathogenesis of MM.