POEMS syndrome (Crow—Fukase syndrome) is a rare lymphoproliferative disease of significant interest to neurologists, since its first and most common manifestation is a progressive demyelinating sensorimotor polyneuropathy. The name of the syndrome reflects the key symptoms: Polyneuropathy, Organomegaly, Endocrinopathy, the presence of M-protein, and Skin changes. The article presents a clinical case of POEMS syndrome in a 32-year-old patient, illustrating the challenging diagnosis. It is emphasized that the disease often remains unrecognized for several years due to the low awareness of doctors about this pathology, as well as the fact that the syndrome may be more common than diagnosed. Particular attention is paid to diagnostic criteria and the importance of careful examination of patients with slowly progressive polyneuropathy of unclear origin or resistant to standard therapy for chronic inflammatory demyelinating polyneuropathy (CIDP). A key diagnostic method is serum protein electrophoresis with immunofixation to detect M-protein. Timely diagnosis and early pathogenetic therapy significantly improve the prognosis of the disease. This clinical case highlights the importance of considering POEMS syndrome in the differential diagnosis of unexplained polyneuropathies.