In 1964, the Council of Ministers approved a financing strategy to promote and develop small industries, as proposed by the National Economic and Social Development Board (NESDB).

A loan processing office for small industries was established under the Department of Industrial Promotion, Ministry of Industry’s supervision to provide financial support to small manufacturing businesses. That office later became the Small Industry Finance Office (SIFO). However, the SIFO’s operations and growth were hampered by limited funds, which were dependent on state budget allocations, and cumbersome and inflexible government procedures and regulations

In 1991, the government promulgated the Small Industry Finance Corporation Act and the SIFO became the Small Industry Finance Corporation (SIFC) with registered capital of Bt300 million. Its status as a juristic person allowed the SIFC to raise capital domestically and internationally.

In 2000, the government initiated policies using the SIFC as the primary mechanism to assist small and medium enterprises, key drivers of the Thai economy. The Ministry of Finance recapitalized the SIFC, increasing its equity to Bt2.5 billion

On December 20, 2002, the Small and Medium Enterprise Development Bank of Thailand Act was enacted, re-establishing the SIFC as the Small and Medium Enterprise Development Bank of Thailand or SME Bank. The Bank’s mandate was “to conduct business with the aim of developing, promoting and assisting small and medium enterprises to start-up expand or improve their businesses by providing loans, guarantees, venture capital, counseling and other necessary services as prescribed by the Act”.

In 2004 , the Ministry of Finance has increased the capital of SME Bank for another 2,000 million baht ; as a result, the share capital of SME Bank was increaseed to 4,800 million baht.

In 2005 , the Ministry of Finance has increased the capital of SME Bank for another 2,500 million baht ; as a result, the share capital of SME Bank was increaseed to 7,300 million baht.

In 2007 , the Ministry of Finance has increased the capital of SME Bank for another 1,200 million baht ; as a result, the share capital of SME Bank was increaseed to 8,500 million baht.

In 2008 , the Ministry of Finance has increased the capital of SME Bank for another 600 million baht ; as a result, the share capital of SME Bank was increaseed to 9,100 million baht.

In 2009 , the Ministry of Finance has increased the capital of SME Bank for another 600 million baht ; as a result, the share capital of SME Bank was increaseed to 11,600 million baht.

In 2012 , the Ministry of Finance has increased the capital of SME Bank for another 600 million baht ; as a result, the share capital of SME Bank was increaseed to 12,200 million baht.

In 2013 , the Ministry of Finance has increased the capital of SME Bank for another 555 million baht ; as a result, the share capital of SME Bank was increaseed to 12,755 million baht.