Fluorescence maxima, fluorescence quantum yields, electrode potentials, and electrogenerated chemiluminescence (ecl) of 16 t‐stilbene derivatives such as substituted indenes and dihydronaphthalenes (DHNP) are reported. Both indenes and DHNP's were found to have greatly enhanced fluorescence quantum yields in comparison to t‐stilbene. Twelve single systems of 16 compounds gave ecl mostly attributed to the singlet excited state. With tri‐p‐tolylamine (TPTA) added as a source of cation radical, most of the systems produced ecl having shorter wavelength emission corresponding to the singlet excited state of the t‐stilbene derivatives and longer wavelength emission attributed to the exciplex. The ecl intensities with respect to the possible applications are discussed.