Background: To detect the radioactive contamination is important for working in a nuclear medicine department not only to prevent and control the contamination of radionuclides but also to ensure the safety of patients and medical staff. Selecting a reliable and suitable radiation detector remains a disturbing issue. In the current study, an experimental method of choosing the optimal radiation detector was described, based on their detection efficiency. Methods: Five available radiation detectors were used in this study, including three area detectors (AL375, AT1121, and ARM-LD) and two personal detectors (Dosi.man and MiniRadiac). Using F-18 FDG as a radioactive source mimicking the radioactive contamination, the effective dose rate of each detector was measured at predetermined distances. The linear regressions of each detector for the effective dose rate and the inverse square of the distance were calculated, and the correlation coefficients of each linear regression were determined. Results: The correlation coefficient was average above 0.9000 in all five radiation detectors. For the two personal detectors, MiniR.adiac showed better detection efficiency. Among the area detectors, the detection efficiency of AT1121 was the best and the most sensitive detector compared to the other four. Conclusion: The radiation detectors used in this study showed similar but distinguished detection efficiency, indicating that this experimental method was suitable for choosing an optimal radiation detector to facilitate the detection and prevention of radioactive contamination. As for the surveillance of patients and visitors with unexpected radioactive contamination in the hospital, such as the emergency department, our experience described here may provide an easy and convenient model for establishing the rapid response to manage the radioactive contamination.