Low-temperature spectra of excitonic emission and recombination dynamics have been studied in ZnSe/CdSe fractional monolayer (ML) superlattices (SLs). Two intrinsic emission bands are observed in SLs with the CdSe layer fraction ranging between 0.5 and 0.7 ML, reflecting inhomogeneity of the SL structure. The emission energies, line widths and decay times are interpreted in terms of random coupling of 1 ML thick extended (with respect to the exciton Bohr radius) CdSe islands in different layers of a disordered SL.