In his youth he dedicated himself to commerce. According to the social norms of the time, he also became a militia officer in the "Regimiento del Rey" (King's regiment). In 1810, while in Lima, he heard of the formation of the Government Junta of the Kingdom, and immediately returned to the country, where he was charged with a diplomatic mission to Buenos Aires. After that successful first mission, he was sent to England, and then to other European countries, with the mission of gathering support for the independence movement. While in Europe he learnt of the news of the defeat of the Chilean army in the Battle of Rancagua and the recapture of Chile by the Spanish troops. He then returned to Argentina to cooperate in the formation of a new army.
Pinto married Luisa Garmendia Aldurralde and had two children, Aníbal Pinto, who would become President of Chile, and Enriqueta Pinto, future wife of President Manuel Bulnes. His grandnephew (and grandson of José Miguel Carrera), Ignacio Carrera Pinto, became a hero at the War of the Pacific.
In 1827, due to the resignation of the President Agustín Eyzaguirre, General Ramón Freire was elected President, while he was elected as Vice President. When General Freire himself resigned on May 5, 1827, General Pinto took over the position as Accidental President. As such he participated in the drafting of the Constitution of 1828.
A new presidential election was called in May 1829. General Pinto was the clear winner out of 9 candidates, with 118 electoral votes (29,06%), and was proclaimed elected on October 19th. Nevertheless, the onset of the Chilean Civil War of 1829 was at hand.
The problem that caused the revolution happened in the vice presidential election. The winner should have been the first runner-up, Francisco Ruiz-Tagle (98 electoral votes or 24,13%), or the second runner-up, General José Joaquín Prieto, (61 votes or 15,02%), both conservatives. Nonetheless, Congress was controlled by the liberals and presided by Francisco Ramón Vicuña, also liberal. Arguing that no vice-presidential candidate had a majority, they selected Joaquín Vicuña, brother of the president of the senate, even though he only got 48 electoral votes (11,82%). That was all the excuse needed by the conservatives to rebel.
Pinto resigned the Presidency on November 2nd (less than 2 weeks after his proclamation), an event that marked his retirement from public life. All his powers were assumed by the President of Congress, Francisco Ramón Vicuña, who was already acting as Accidental President since July 16, 1829, when Pinto had delegated his powers on him for the duration of the electoral campaign.
Pinto only returned to public life in 1841, as a congressman. The Liberal party proclaimed him as a candidate to the Presidency in the Chilean presidential elections of 1841, in opposition to General Manuel Bulnes, whom finally resulted elected. He did not participate in the campaign in any active form. Nonetheless he was elected a Deputy for La Serena, and President of the Chamber, on May 30, 1843. He was elected a Senator in 1846, and became a member of the permanent war and navy commission. He was also named Privy Council by President Bulnes.