A native of St. Louis, Missouri, Reiser originally signed with his hometown Cardinals, but at age 19 he was among a group of minor league players declared free agents by Commissioner of Baseball Kenesaw Mountain Landis. Reportedly, Cardinal general manager Branch Rickey—mortified at losing a player of Reiser's caliber—arranged for the Dodgers to sign Reiser, hide him in the minors, then trade him back to St. Louis at a later date. But Reiser's stellar performances in spring training in both 1939 and 1940 forced the Dodgers to keep him.^[1] (Rickey would become GM of the Dodgers after the 1942 season and witness Reiser's injury-caused decline as a great talent.)

In 1941, his first season as a regular starter, Reiser helped the Dodgers win the pennant for the first time since 1920. He was a sensation that year, winning the National League batting title while leading the league in doubles, triples, total bases, runs scored and slugging percentage. He was also named a starter to the All-Star team^[2] and placed second in MVP balloting.^[3] On July 19 of the following year, Reiser crashed face-first into the outfield wall in St. Louis, trying to catch what turned out to be a game-winning inside-the-park home run by Enos Slaughter of the rival Cardinals in the bottom of the 11th inning.^[4] The loss cut the Dodgers' lead over the Cardinals to six games.^[5]

Despite missing just four games with the resulting concussion, he batted only .244 over his final 48 games that season, dropping his batting average from .350 to .310 for the year.^[6] The Dodgers ended up losing the pennant by two games to the Cardinals, who won 20 of their last 23 games and eventually the World Series.^[7]

Reiser gave great effort on every play in the field, and was therefore very injury-prone. He fractured his skull running into an outfield wall on one occasion (but still made the throw back to the infield), was temporarily paralyzed on another, and was taken off the field on a stretcher a record 11 times.

Leo Durocher, who was Reiser's first major league manager, reflected many years later that in terms of talent, skill and potential, there was only one other player comparable to Reiser: Willie Mays. He also said, "Pete had more power than Willie—left-handed and right-handed both. Willie had everything, Pete had everything but luck."^[8]

Reiser, a switch hitter who sometimes restricted himself to batting left-handed because of injury, served in the United States Army during World War II, playing baseball for Army teams. While serving, he was injured again and had to learn to throw with both arms. Durocher said, "And he could throw at least as good as Willie [Mays, both] right-handed and left-handed."

When Reiser returned to the majors in 1946, he was still suffering from a shoulder injury from playing Army baseball.^[9] He later said: "It wasn't as serious as the head injuries, but it did more to end my career. The shoulder kept popping out of place, more bone chips developed, and there was constant pain in the arm and shoulder."

He was never the same hitter he was early in his career, but was still as fast as ever, stealing home a record seven times in 1946. In 1948, Ebbets Field became the first ballpark with padded outfield walls due to Reiser's penchant for running into them.^[10]

Reiser managed in the minors for several years (including the Kokomo Dodgers in 1956–57,^[11][12] among others), winning the 1959 Minor League Manager of the Year Award from The Sporting News. While working with the Green Bay Dodgers as the team's manager, he urged a young clubhouse manager named Joe Proski, who was on a football scholarship for Montana State University at the time, to pursue a career in athletic training.^[13] His advice helped lead Proski to working with the Detroit Tigers and Chicago White Sox for spring training periods and then with the Chicago Cubs in a full-time position for eight years before later moving to the NBA with the Chicago Bulls for one season and then the Phoenix Suns for the rest of his career afterward until his retirement in 2000, with Proski being honored for his time spent with Phoenix. He served as a coach on Walter Alston's Los Angeles Dodger staff from 1960 to 1964 (including the 1963 world championship team). However, he was forced out in 1965 as manager of the AAA Spokane Indians as the result of a heart attack. His replacement was Duke Snider—the man who had once replaced him as Brooklyn Dodger center fielder.

When Leo Durocher became manager of the Chicago Cubs in 1966, he brought many of his former players to coach on his staff. Reiser was one of them (1966–1969; 1972–1974). He also coached for the California Angels in 1970–71.

In 1981, Lawrence Ritter and Donald Honig included him in their book "The 100 Greatest Baseball Players of All Time." They used what they called "Smoky Joe Wood Syndrome" to explain why a truly exceptional player whose career was curtailed by injury—despite not having had career statistics that would quantitatively rank him with the all-time greats—should nonetheless be included on their list.

Reiser died in Palm Springs, California, of respiratory disease at 62, and was buried at Desert Memorial Park in Cathedral City, California.^[14]

• List of Major League Baseball batting champions
• List of Major League Baseball annual runs scored leaders
• List of Major League Baseball annual stolen base leaders
• List of Major League Baseball annual doubles leaders
• List of Major League Baseball annual triples leaders

• Honig, Donald (1975) Baseball When the Grass Was Real: Baseball from the Twenties to the Forties Told by the Men Who Played It. New York: Coward, McGann & Geoghegan. pp. 283–315. SBN 698-10660-1.

• Career statistics and player information from MLB, or ESPN, or Baseball Reference, or Fangraphs, or Baseball Reference (Minors), or Retrosheet
• Pete Reiser at the SABR Baseball Biography Project
• Pete Reiser at The Deadball Era^{[dead link]}
• Pete Reiser at Find a Grave