Spectral and photophysical properties of xanthione and pyranthione in micellar systems (SDS, CTAB, SPFO) have been studied and compared to their properties in polar and nonpolar solvents. It has been proved that xanthione, characterized by a very rich absorption and emission spectra, covering the range from 200 to 900 nm, related to its electronic states (T-1(n, pi*), T-2(pi, pi*), S-1(n, pi*), S-2(pi, pi*), S-3(pi, pi*)) and showing, moreover, high sensitivity to environmental conditions makes a very convenient absorption and emission probe for investigation of the structure and properties of micellar systems.