The phosphorescence properties of hemocyanin from Levantina hierosolima were studied. From the intensity spectrum and the lifetime values at different wavelengths, the triplet emission energy was resolved into its tyrosyl and tryptophanyl components. A comparison of the emission characteristics of each amino acid in apohemocyanin, deoxygenated hemocyanin, and oxygenated hemocyanin was carried out. It was found that copper increases the tyrosyl quantum yield but does not affect the tryptophanyl emission. In contrast, oxygenation quenches the phosphorescence of both tyrosyl and tryptophanyl residues. Energy pathways in the hemocyanin molecule are discussed.