Background: The present study aimed to investigate the dependence of the response of the genipin gel dosimeter on readout temperatures. Materials and Methods: To this aim, after the gel preparation, they were exposed by a Varian Medical Linac accelerator with a dose range of 0-10 Gy. Then the irradiated samples were readout by a spectrophotometer device at 5°C, 10°C, 15°C and 20 °C temperatures. Results: Results revealed that the response of the genipin gel dosimeter is extremely temperature-dependent. For the mentioned readout temperatures, the maximum dose sensitivity was related to 10°C and its value was 35×10^-3cm^-1Gy^-1. Investigation of the AUS (area under spectra) depicted that the maximum dose sensitivity was also related to 10°C. Furthermore, investigation of the dose resolution of this gel dosimeter showed that the minimum detectable dose was related to 10°C, and its amount was 0.24 Gy. Conclusion: The results confirmed a noticeable change in the response of the genipin gel dosimeter due to variations of the readout temperature. It can be concluded that the response sensitivity of this radiochromic gel dosimeter increased by readout temperature decreasing.