Manganese-doped zinc gallate is a new promising cathode ray phosphor material with low excitation voltage. On excitation of the host, we observed strong emission from both the self-activated (SA) host material and tetrahedrally coordinated Mn2+ ions in single-crystal fibers. The efficient host-Mn2+ energy transfer makes this material an attractive candidate for display technology. The experimental results show that the SA center is not an intermediate involved in the host-Mn2+ energy-transfer process.