Methods and associated structure for providing broadcast of PCI bus transactions using device ID messaging (DIM) features of the PCI bus specifications. A vendor defined class of messages are defined using device ID messaging to provide broadcast of messages across PCI bus bridge devices to multiple PCI bus segments. One aspect hereof provides for using implicitly addressed device ID messaging such that bridge devices, compatible with the vendor defined message classes, will forward the message upstream and downstream. Another feature provides for use of explicitly addressed device ID messaging to effectuate the desired broadcast. Another aspect hereof provides for translation of a received DIM formatted message with broadcast information and applying the broadcast information to a second bus segment as a standard PCI broadcast transaction.