Martínez Trueba was born in Montevideo and grew up in the Peñarol area, graduating from university with a degree in pharmaceutical chemistry.

He pursued a career as an army officer, and was a member of the Colorado Party, which ruled Uruguay for long periods.

He was the president of Banco de la República Oriental del Uruguay from 1948 to 1950.

In 1952 the new Constitution created the National Council of Government (Uruguay), and Martínez Trueba presided over it till 1955.

[7] That same year a pension fund was set up for university professionals while a law was passed that, as noted by one study, “finally included all workers in the private sector in social security.”[8] As a result, death, invalidity and old age pensions were provided for all workers.