The applicability of plastic scintillation fibers as a radiation position detector is evaluated for low‐energy x‐ray irradiation. A continuous x‐ray generator with a copper anode is used as a source radiating very intense lines: Kα2=8.02 keV, Kα1=8.04 keV, Kβ1=8.9 keV. A microchannel intensified tube followed by a vidicon camera is used as the photodetector for scintillation light guided to both extremities of a fiber detector. A one‐dimensional position‐sensitive radiation detector is constructed as an application. The irradiation position is derived independently of the system operating conditions (gain, sensitivity, efficiency) with a relative error smaller than 4%. Using this device, the optical attenuation length is measured with a relative error less than 10%. The differences in the photon distribution at fiber terminating faces are discussed for light and for x‐ray excitations with respect to their incidence angles.