A system and method can support across-domain messaging in a transactional middleware machine environment. A transaction domain can import one or more services from a remote transaction domain, wherein said one or more services are registered in a service table that is associated with the transaction domain. Furthermore, a client in the transaction domain can find from the service table a remote server in the remote transaction domain that provides said one or more services, and send a message directly to the remote server to invoke said one or more services by passing one or more domain gateway servers in both the transaction domain and the remote transaction domain.