Thin films of cadmium sulphoselenide (CdSSe) have been chemically deposited using cadmium salt, thiourea and sodium selenosulphate, covering total composition range from CdS to CdSe. The structural, optical and electrical properties of these films have been studied. It has been found that CdS films are cubic, while mixed (CdSSe) and CdSe films are hexagonal. The optical absorption studies showed that as Se content in CdS film increases, bandgap, E-g decreases from 2.5 eV (CdS) to 1.8 eV (CdSe). The electrical resistivity of CdS is higher than that of mixed and CdSe films.