Tanzania Official Seed Certification Institute (TOSCI) is a government institute under the Ministry of Agriculture (MOA) established by the Seed Act No. 18, 2003. TOSCI is responsible for the certification and promotion of quality agricultural Seeds produced or imported into the country for sale. It is also entrusted with safeguarding farming community from procuring poor quality or fake seeds from vendors of farm inputs.

TOSCI headquarters is currently located at the main campus of Sokoine University of Agriculture (SUA) in Morogoro. TOSCI has four branches at Arusha, which serves for the Northern zone, Njombe serving the Southern highlands zone, Mwanza which serves the Lake and Western Zones while Mtwara serving the Southern zone.

TOSCI is a result of transformation from Tanzania Official Seed Certification Agency (TOSCA) which was established by the Seed Act 1973. The transformation of TOSCI from TOSCA was a result of government reforms initiatives to increase efficiency of public institutions. The Seeds Act of 1973 was reviewed and replaced by Seeds Act No. 18 of 2003 in order to incorporate private sector, and joining both International Seed Testing Association (ISTA) for seed testing procedures and Organization for Economic Cooperation and Development (OECD) Seed Schemes as a requirements for facilitating international seed trade.