The present work attempts to synthesize Zn doped Bismuth Oxide thin films deposited effectively on to micro glass substrates at different bath temperatures by Chemical Bath Route. The films were characterized by XRD, SEM, EDAX and optical analysis. XRD analysis reveals that all the films belong to monoclinic in polycrystalline structure with preferred orientation along (012). The optical energy gap values of Zn doped Bi2O3 thin films were in the range 2.21- 2.81 eV which depend on deposition temperatures. Zn - Bi2O3 thin films can be used in photo voltaic cells, gas sensors, optical coatings, flat-panel displays, micro electronics, light emitting diodes, batteries, super capacitors and fuel cell industries.