The study examined the establishment, survival, and the transformation of Wema Bank from Agbonmagbe in the colonial time, to Wema Bank in the post colonial economy of southwest Nigeria. The inter World Wars economic situation, the lopsided and deprived access to finance during the period, led to the establishment of the Bank as the second indigenous bank in 1945; as against the period 1892 to the 1940s when imperial banks dominated and controlled the economy. With the use of oral interview, archival, and secondary materials, using "political economy" and "structural function" theories, the study established that the bank was important to the Western Regional government development policy. Thus from the period of 1954 - 1962, with the government support, the bank grew and had impact in the economic success of the Region. The combination of economic and political plans of the region becomes explicit in the management of the Regional Marketing Board and the indigenous banks in raising the standard of merchants and business people in Southwestern Nigeria. The pursuit of economic and political success through government investment in the bank, led to socio-economic developments especially in the educational sector. However, political crisis in the region in the first decade of independence threatened its survival hence, government‟s takeover of the bank in 1969.