In this study, we have developed an efficient metamaterial (MTM)-based portable fuel oil sensor in order to distinguish branded and unbranded fuel-oil samples. Electromagnetic properties of the fuel-oil samples are experimentally obtained and these data are defined in numerical analysis to design and test the performance of MTM sensor. Then, simulated MTM-based sensor structure is fabricated and measured to observe the efficiency and agreement to numerical results. Numerical and experimental studies are conducted in the microwave frequencies of 10-11 GHz. The experiment results are in accordance with the simulation ones. It can be seen from the results that the proposed MTM-based sensor can be implemented into the sensor industry for distinguishing the branded and unbranded fuel oil for several frequency regions.