<b><i>Objectives:</i></b> To estimate the direct and indirect factual costs of polyneuropathy in a national sample of patients and their spouses based on a national register-based cohort study with matched controls. <b><i>Methods:</i></b> Using records from the Danish National Patient Registry (1997-2009) all patients with a diagnosis of polyneuropathy and their partners were identified and compared with randomly chosen controls matched for age, gender, geographic area and civil status. Direct costs included frequencies of primary and secondary sector contacts and procedures, and medication. Indirect costs included the effect on labor supply. Social-transfer payments were included to illustrate the effect on national accounts. All cost data were extracted from national databases. <b><i>Results:</i></b> 13,758 unspecified polyneuropathy patients were registered. They were compared with 54,900 matched controls identified from the National Danish Patient Registry. In addition, partners of patients in the case group were matched with partners in the corresponding control group. Almost half of the patients in the patient group had a partner. Patients had significantly higher rates of health-related contacts, medication use and greater socioeconomic costs than controls. They had very marginally lower employment rates, and those who were employed generally had lower incomes. The sum of direct net healthcare costs after the injury (general practitioner services, hospital services and medication) and indirect costs (loss of labor market income) was €12,647 for patients and €2,984 for their partners over and above that of controls. Social-transfer payments were all significantly larger in patients than in control subjects. Furthermore, the patients already exhibited a negative social- and health-related status up to eleven years before the first diagnosis, particularly for those with the highest costs. The health effects were present in all age groups and in both genders. <b><i>Conclusions:</i></b> Patients with a diagnosis of polyneuropathy experience increased mortality, morbidity and socioeconomic consequences. i 2014 S. Karger AG, Basel