Background Studies have revealed an association between overweight/obesity and multiple myeloma. However, the factors linking a dysregulated energy metabolism to this disease have not been identified. Adipose tissue produces and secretes the adipokines leptin, adiponectin and resistin, involved in metabolism and cell growth. Methods We measured the plasma concentrations of these three adipokines in newly diagnosed multiple myeloma as well as in patients with relapse. We further explored the importance of leptin in multiple myeloma by performing gene expression profiling in two myeloma cell lines. Results At diagnosis, leptin was increased (P Conclusions The plasma concentrations of leptin and adiponectin, but not resistin, were abnormal in newly diagnosed multiple myeloma. Adipose tissue may modify the growth and metabolism of myeloma cells through adipokine-mediated effects.