Electron energy loss spectroscopy (EELS) and ultraviolet photoemission have been used to study the electronic structure of ZnSe(100) surfaces. Changes in both the occupied states and electronic transitions are observed upon passing from the disordered, Se-saturated (1 × 1) surface to ordered Se-stabilized (2 × 1) and Zn-terminated c(2 × 2) reconstructions. In particular, the (2 × 1) surface is found to exhibit a lower onset of interband transitions than both the c(2 × 2) phase and bulk ZnSe. The smaller surface band-gap for this surface can be attributed to transitions involving Se dimer states lying within the bulk gap.