Unirradiated tartaric acid samples do not exhibit any ESR signal. However, the ESR spectra of irradiated samples contain many resonance signals. The dose-response curves of the resonance signals, denoted as I-1, I-2, I-3 and I-4 in the present study, were found to increase linearly with the applied radiation dose in the range of 0.04-25 kGy. Adjusting the microvawe power and modulation amplitudes of 1.0 mW and 1.0 mT, respectively, was found to increase the sensitivity of tartaric acid. From the dose-response curves and room temperature decay data, it was concluded that the I-3 resonance signal of tartaric acid can be used for dose measurements at intermediate (0.04-0.4 kGy) and high dose (0.5-25 kGy) levels.