Polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes (POEMS) syndrome is a rare paraneoplastic disorder associated with an underlying plasma cell dyscrasia and multiorgan failure. POEMS syndrome is potentially fatal and adversely affects quality of life. Oedema is common with many patients affected by pleural effusions, ascites and lower limb oedema. Bioelectrical impedance vector analysis (BIVA) is a non-invasive assessment tool, which enables rapid bedside assessments of nutrition and hydration. This paper describes the use of sequential BIVA assessments to evaluate the response to diuretic therapy in a woman aged 52 years with POEMS syndrome. This case illustrates the potential to use BIVA to conduct longitudinal assessments of hydration status. This provides opportunities for further research using BIVA to monitor hydration and response to interventions. This may be useful in specific situations, for example at the end of life.