[en] Radioactive sources are used in many sectors of the Nigerian economy. All the radioactive sources used in the country are imported. The Nigerian Nuclear Regulatory Authority (NNRA) was established in 2001 by the Nuclear Safety and Radiation Protection Act 1995. The Act confers on the NNRA the statutory function for the safety and security of radioactive sources. Through the Act and all its enabling powers, these functions are carried out through the NNRA regulatory control programme comprising regulations and guidance; authorization; oversight functions; emergency planning and response; and ancillary functions. Nigeria has experienced incidents involving loss of control and/or subsequent illegal transboundary movement of radioactive sources in the past. The NNRA has therefore strengthened its regulatory control programme and improved on safety and security, thereby preventing illicit trafficking of radioactive materials by the gazetting of the Nigerian Safety and Security of Radioactive Sources Regulation 2006, Nigerian Transport of Radioactive Sources Regulation 2006 and the Nigerian Radioactive Waste Management Regulation 2006. Significant positive achievements have been recorded in this regard owing to cooperation between the NNRA, law enforcement and governmental agencies including the Federal Ministry of Justice, the Department of State Services, the Nigeria Customs Service, the Nigerian Police Force and the National Emergency Management Agency. Further restrictions have also been made on the entry into and exit from the country of radioactive sources by the designation of certain airports and seaports. The above successes notwithstanding, enhancing national capabilities in the area of detection at the ports of entry and international cooperation leading to the exchange of information between importing and exporting countries of radioactive sources, among others, still remain a challenge. The IAEA's ongoing programme on the upgrading of nuclear security infrastructure in Nigeria is also mentioned. (author)