Heptamethine Iodide and heptamethine hexafluorophosphate solutions in various solvents (chloroform, dichloromethane, ethanol and toluene) were studied spectrophotometrically and spectrofluorimetrically as X-ray and gamma-ray dosimeters for the detection of low-dose radiation. The useful dose range was found to be between 0 to 1 Gy and 1 to 30 Gy for the concentrations studied. The effects of temperature and light on the stability of response during pre-irradiation and post-irradiation storage, the effects of different solvents and dose rates on dosimetric responses of these dyes were also investigated. The results of our studies show that these dye solutions are quite stable in the dark at low as well as room temperature and could be used as dosimeters for low dose X-ray and gamma radiation in medical dosimetry for radiotherapy treatment planning. They can also be used as dosimeters in personal radiation safety applications and environmental radiation monitoring. They have constant sensitivity and their detection limit is an order of magnitude lower than recently reported in the literature. These dyes are and were used in photography industry, so they are cheap and easy to buy.