POEMS syndrome is a rare multisystem disease associated with an underlying plasma cell disorder. Its name is an acronym for peripheral neuropathy (P), endocrinopathy (E), organomegaly (O), monoclonal plasma cell proliferative disorder (M), and skin changes (S). This case report describes a patient with POEMS syndrome who presented with progressive fatigue and numbness in the lower extremities. Initially, the patient was erroneously diagnosed with diabetes and diabetic peripheral neuropathy because of the endocrinopathy associated with POEMS syndrome. After a second hospitalization, the patient was diagnosed with POEMS syndrome and recovered with alkylator therapy and a peripheral blood stem cell transplant. The patient’s overall condition was improved at the 1-year follow-up. POEMS syndrome should be considered if a patient presents with endocrinopathy and unexplained peripheral neuropathy.