Banestes success story began on August 9, 1935, when the then state governor Major João Punaro Bley created the INSTITUTO DE CRÉDITO DO ESPÍRITO SANTO (ESPÍRITO SANTO AGRICULTURAL CREDIT INSTITUTE) through Decree 6639, to undertake farming and land-purchase loans and similar operations.

On June 17, 1936, Law 68 established the amounts that would go towards the foundation or initial capital of this Institute which would preferably be invested in the formation of a company or bank that would maintain a portfolio of farming loans at reasonable interest to encourage the development of agriculture in the state.

Thus, on April 30, 1937, BANCO DE CRÉDITO AGRÍCOLA DO ESPÍRITO SANTO was established as a corporation by public deed, with head offices in Vitória and an initial capital of RS5,000:000$000 (five thousand contos de réis) divided into 50,000 registered common shares worth RS.100$000 (one hundred thousand réis) each, fully paid-in at the time by 93 shareholders. The same deed contained the Bank's first Bylaws, listing the shareholders, led by the Espírito Santo state government, with 49,249 common (ON) shares, or 98.49% of the total capital. The remaining shareholders retained 751 ON shares, or 1.51% of the total. Through Decree-Law 8841 of December 29, 1937, the state government guaranteed the deposits in the new institution.

For more than 30 years after its foundation, the Bank was a closely-held corporation, i.e. its shares were not traded on the stock market but on the over-the-counter market. During this period, given the Bank's rapid growth in the first few years, when it opened numerous new branches, both inside and outside the state, various capital increases were effected, some of which through new share issues. As a result, the number of shares and shareholders increased substantially.

In 1969, the Bank's name was altered to BANCO DO ESTADO DO ESPÍRITO SANTO S.A. In the following year, pursuant to article 9 of Law 4595 of December 31, 1964, and article 59 of Law 4728 of July 14, 1965, it requested authorization from the Central Bank to operate as a publicly-held corporation.

On April 14, 1970, the Central Bank (through GEMEC/R/69/3818) certified that Banestes met all the conditions of a publicly-held corporation and authorized it to operate as such, thereby granting numerous advantages to its shareholders, including the tradability of its shares in any stock market in Brazil.

As of then, the Bank's shares have been traded in various Brazilian stock exchanges, including those in Rio de Janeiro, Minas-Espírito Santo-Brasília and Bahia-Sergipe-Alagoas. On July 20, 1977, they were listed on the São Paulo Stock Exchange, where they are still traded.

On October 15, 1978, to commemorate the Bank's 40th anniversary, the Executive Board granted a bonus to all employees, partly in cash and partly in shares, proportionate to their time of service. As a result, all the institution's personnel at the time became shareholders, raising the total from 2041 to 5069.

Until the mid-1960s, there were 27 stock exchanges in Brazil, based in the state capitals and run by the state governments through their finance departments. Brokers were also nominated by the public authorities. However, as the stock market began to expand, a series of integration agreements were signed and, as of 2000, the Bovespa became the only exchange in Brazil on which shares were traded. The remaining regional exchanges concentrated on market development and the provision of local services.

Currently, Banestes has around 9000 shareholders, with the Espírito Santo state government holding 92.14% of the total capital. The Bank's capital stock comprises 109,305,235 registered common shares and 42,183,218 registered preferred shares, totaling 151,488,453 shares.