Crystalline　zinc　sulfide　(ZnS)　thin　films　were　prepared　by　chemical　bath　deposition　(CBD)　using　the　mixed　aqueous　solutions　of　zinc　acetate,　thiourea　and　tri-sodium　citrate,　where　tri-sodium　citrate　was　used　as　the　complexing　agent.　The　thin　films　were　characterized　by　x-ray　diffraction　(XRD),　scanning　electron　microscopy　(SEM)　and　optical　absorption.　The　as-deposited　thin　films　were　surface　homogeneous　with　pure　wurtzite　structure　and　the　optical　band　gap　of　the　film　was　estimated　to　be　3.53　eV.