Provided are a method and apparatus for decoding a multiview video and a method and apparatus for encoding a multiview video. The decoding method includes: receiving multiview image streams that configure the multiview video; obtaining, from a predetermined data unit header that includes information of a base-view picture included in a base-view image stream, picture order count (POC) information of the base-view picture; determining, using the POC information of the base-view picture, a POC of the base-view picture, based on an instantaneous decoding refresh (IDR) picture of a base-view; and determining, using the POC of the base-view picture, a POC of an additional-view picture that is included in a same access unit as the base-view picture and is transmitted.