Dosimetric response and post-irradiation stability of commercially available 2 mm thick polymethyl methacrylate sheets have been investigated spectrophotometrically. The response curves at 615, 650 and 700 nm show linear response from 4 to 15 kGy. At 640 nm the response is linear from 4 to 20 kGy and with proper calibration, the dosimeter can be used up to 50 kGy. The stability of response of red PMMA dosimeter during post-irradiation swage at different storage temperature (-10, 26,35, 40, 50-degrees-C) has also been investigated at 640 nn. The dosimeters irradiated to 10 or 20 kGy and stored al room temperature show stable response for about three weeks, which is followed by slight and gradual decrease in response. The response during post-irradiation storage at lower temperature (-10 to 35-degrees-C) is stable over a period of 15 days while at higher temperature (45 and 55-degrees-C), fading of colour takes place which is faster at higher temperatures. These results show that the dosimetric characteristics of commercially available 2 mm thick red PMMA sheets are suitable for its possible application in radiation processing, such as sterilization of medical supplies and food irradiation, however storage of dosimeters at temperatures above 35-degrees-C should be avoided.