The triplet excited state of the 9-phenylxanthenium cation has been observed directly by both luminescence and transient absorption techniques. The triplet–triplet absorption shows λmax ≤ 300 nm and decays over a period of several microseconds in the absence of easily oxidized donors. The triplet cation reacts with 9-phenylxanthydrol and biphenyl via electron transfer to give the corresponding radical and radical cation and also reacts rapidly with both oxygen and 1,3-cyclohexadiene. Keywords: carbocations, triplets, electron transfer, laser flash photolysis.