[en] The Nigerian Nuclear Regulatory Authority (NNRA) is charged with the overall responsibility for nuclear safety and radiological protection regulation in the country. It regulates the possession and application of radioactive substances and devices emitting ionising radiation; ensures protection of life, health, property and the environment from the harmful effects of ionising radiation, while allowing beneficial practices involving exposure to ionising radiation. The practices involving the use of radioactive sources predates the establishment of the NNRA by several decades with the petroleum industry making the most extensive use of radioactive sources for non-destructive testing, well logging and in control gauges. Other applications of sources are in medical, which include radiotherapy and nuclear medicine, agriculture, education and research and there are several thousand sources that are also used as gauges in the manufacturing industry. The NNRA considers three fundamentals as challenges for safety and security of radioactive sources in Nigeria and these are developing an appropriate regulatory system, implementing the regulatory system and the establishment of measures to address the potential for loss of control of radioactive sources. (author)