The dosimetric characteristics of a commercially available radiochromic thin plastic film (Gafchromic) dosimeter have been evaluated spectrophotometrically. The response curves at longer wavelengths (596 and 650 nm) show a linear response up to an absorbed doses of 2 kGy, whereas the response curves at shorter wavelengths (350, 375, 400, 450, 500 nm) are linear up to 5 kGy. If stored at room temperature (ca. 25-degrees-C) in dark, the pre-irradiation shelf-life of the film is more than 30 months. The dosimetric film also shows stable behaviour up to 40 days during post irradiation storage at room temperature in dark. The response is stable at lower temperature (-10 and 7-degrees-C) at 596 nm but shows some variations at 650 nm at higher doses, while at higher temperature (40-degrees-C) the response is unstable. The response shows increase in absorbance as the radiation chamber temperature increased from 0 to 46-degrees-C.