Playing in the major leagues for 20 years, Valo was a .282 hitter with 58 home runs and 601 RBI in 1806 games, with most of his time spent as a member of the Philadelphia & Kansas City Athletics (1940-43, 1946-56).

Valo also played with the Philadelphia Phillies (1956, 1961), Brooklyn & Los Angeles Dodgers (1957-58), Cleveland Indians (1959), New York Yankees (1960), and Washington Senators/Minnesota Twins (1960-61). His last game was on October 1, 1961, with the Phillies.

A native of Ribnik, Czechoslovakia, Valo was a hustling player and an aggressive line-drive hitter who hit .300 or better five times, with a high-career .364 in 1955. As a right fielder, he was noted for his fearless manner in challenging fences, and occasionally crashed through an outfield wall in pursuit of a ball.

On May 1, 1949, Valo became the first player in the American League to hit two bases-loaded triples in a game. He added a third bases-loaded triple in the same season, to tie the mark set by Shano Collins in 1918. Years later, the mark of two bases-loaded triples in a game has been matched only by Bill Bruton (NL, 1979) and Duane Kuiper (AL, 1978). He also hit for the cycle in 1950, and belted three home runs in a game a year later; but as Valo's career moved into its final phase, he became an outstanding pinch-hitter. He used his strike zone judgment to post an on base percentage over .400 in eight of the ten seasons (.414 from 1946-55).

In 1960, Valo set a major league pinch-hitting season-records for games, walks and times on base. He also set a major league career-record with 91 walks for a pinch-hitter.

Following his retirement as a player, Valo worked with the Indians' organization as a minor league manager, and served as a scout for the Phillies for 13 years, until the time of his death.

Elmer Valo died at Palmerton Hospital in Palmerton, Pennsylvania, at age of 77. He was inducted into the Phillies Wall of Fame, at Veterans Stadium, in 1990.