Gamma-rays (gamma-rays), wherever present, e.g., in medicine, nuclear environment, or homeland security, due to their strong impact on biological matter, should be closely monitored. There is a need for simple, sensitive gamma-ray detectors at affordable prices. Here, it is shown that gamma-ray detectors based on crystals of methylammonium lead tribromide (MAPbBr(3)) ideally meet these requirements. Specifically, the gamma-rays incident on a MAPbBr(3) crystal generates photocarriers with a high mobility-lifetime product, allowing radiation detection by photocurrent measurements at room temperatures. Moreover, the MAPbBr(3) crystal-based detectors, equipped with improved carbon electrodes, can operate at low bias (approximate to 1.0 V), hence being suitable for applications in energy-sparse environments, including space. The gamma-ray detectors reported herein are exposed to radiation from a Co-60 source at dose rates up to 2.3 Gy h(-1) under ambient conditions for over 100 h, without any sign of degradation. The excellent radiation tolerance stems from the intrinsic structural plasticity of the organic-inorganic halide perovskites, which can be attributed to a defect-healing process by fast ion migration at the nanoscale level. The sensitivity of the gamma-ray detection upon volume is tested for MAPbBr(3) crystals reaching up to 1000 cm(3) (3.3 kg in weight) grown by a unique crystal growth technique.