The fluorescence with maximum at 683 nm from isolated yeast plasma membranes has been detected. The fluorescence was due to a membrane-bound compound absorbing in the visible range of the spectrum. The fluorescence excitation spectrum of this compound has a structure typical for porphyrins. At the same time, in several fluorescence properties the porphyrin localized in the plasma membrane is different from other intracellular porphyrins (protoporphyrin, coproporphyrin).