Four structural polypeptides of Hazara virus, an agent closely related to the Crimean-Congo haemorrhagic fever (C-CHF) viruses, were resolved by SDS-polyacrylamide gel electrophoresis. Three glycoproteins were identified (mol. wt. 84,000, 45,000 and 30,000) and were found to be associated with the virion envelope. A fourth polypeptide (mol. wt. 52,000) was non-glycosylated and associated with the nucleocapsid. The structural proteins of Hazara virus differ markedly from those reported for other bunyaviruses.