Oil tanks are one of the most important targets in remote sensing. Oil tank detection using optical images has been developed in recent years, but few methods have been studied for oil tank detection in synthetic aperture radar (SAR) images. Optical methods suffer incorrect assessments or false alarms when they are applied in SAR imagery. A method that combines the quasi-circular shadows and highlighting arcs is proposed to detect oil tanks with higher precision and lower false alarm. In general, a highlighting arc caused by the double reflection exists exactly at the bottom of each cylinder tank in a SAR image, so it can be employed to detect the oil tanks. However, it is very difficult to detect those arcs directly. Additionally, each cylinder tank has a quasi-circular shadow area in SAR image, which is near the highlighting arc and is easy to be detected. Cylinder tank can be detected by taking advantages of a corresponding quasi-circular shadow area in SAR image, instead of detecting a highlighting arc directly. This research proposes to detect the quasi-circular shadow first, then find the strong scattering point around the shadow areas, and finally shift the edge of the detected circle to its corresponding strong scattering point. This leads to low false alarm oil tank detection in SAR imagery. Analysis of TerraSAR-X images allows a limited validation of the method proposed.