POEMS syndrome is often associated with a poor prognosis. Elevated serum vascular endothelial growth factor (sVEGF) is a useful diagnostic marker with high sensitivity and specificity. However, the relationship between sVEGF elevation and polyneuropathy in POEMS syndrome remains controversial. We herein report a case of polyneuropathy without sVEGF elevation at the first admission. However, at 21 months after the onset, the patient tested positive for sVEGF and was diagnosed with POEMS syndrome. Therefore, it is important to repeatedly measure sVEGF levels in patients with polyneuropathy with an atypical course when POEMS syndrome is suspected, even if the initial sVEGF level is normal.