Martínez came through the youth team of local side Sportivo Alba de Victoria and signed on as a youth player for Nacional in 1962. After playing for Nacional at various youth levels and for the first team he joined Racing Club de Montevideo in 1947.
It was with Peñarol that Martínez enjoyed most of his success at the club level. During his time with the club he captained the team to five consecutive league titles (1958–1962), two Copa Libertadores (1960, 1961), the Copa Intercontinental in 1961 and four consecutive editions of the Copa Uruguay (1958–1961).
In 1963 Martínez returned to Rampla Juniors, in 1967 he joined Atlético Junior in Colombia before returning for a third spell with Rampla Juniors.
In the last years of his playing career he worked as the player-manager of Fenix and Central Español. He retired from football in 1970 at the age of 42.
International career
Martínez was in the Uruguay squads for three FIFA World Cup tournaments (1950, 1954 and 1962). He played a total of 54 matches scoring 2 goals.