The possibilities of using modern photon and neutron detectors for developing radiation monitors, specifically, LaBr3, Bi4Ge3O12, CdWO4, LiI, ZnO, Lu2SiO5(Ce), CdTe, and HgI2, microtubes from organic scintillators, nanomaterials, and detectors based on gaseous and solid-state electronic multipliers are examined. A comparison is made of conventional detectors based on NaI(Tl) and CsI(Tl), plastic scintillators, and 3He counters. The advantages of the new detectors are better energy resolution, high detection efficiency, low supply voltage, processing convenience, and cost. These detectors will increase the sensitivity of radiation monitors in monitoring unauthorized transport of nuclear and other radioactive materials, identify in real time the materials being monitored, and simplify the detecting apparatus and the development of monitors.