This review summarizes the background and recent status of the fuel cell electric bus (FCEB) demonstration projects in North America and Europe. Key performance metrics include accumulated miles, availability, fuel economy, fuel cost, roadcalls, and hydrogen fueling. The state-of-the-art technology used in today's fuel cell bus is highlighted. Existing hydrogen infrastructure for refueling is described. The article also presents the challenges encountered in these projects, the experiences learned, as well as current and future performance targets.