Soon after the 6'-2" (1.89 m), 240-pound (108.8 kg) Ted Kluszewski joined the Reds, he cut off the sleeves of his uniform, much to the chagrin of the Reds front office. He did it because the tight sleeves constricted his large biceps and shoulders and interfered with his swing. "They got pretty upset, but it was either that or change my swing — and I wasn't about to change my swing", said Kluszewski. Ted Kluszewski also became notorious for his strength. When Hall of Fame manager Leo Durocher was once asked by a writer to name five of the strongest players in baseball, he complied. However, when the writer pointed out that he'd left Ted Kluszewski off the list, Durocher huffed and said: "Kluszewski? I'm talking about human beings!"
Ted Kluszewski was selected as an All-Star in four seasons, and was a career .298 hitter with 279 home runs and 1028 RBI in 1718 games. In ten of his fifteen seasons, Kluszewski walked (492) more often than he struck out (365). In 1955, he hit 47 homers while striking out only 40 times. No player since him has hit 40 homers and struck out 40 or fewer times in the same season (Barry Bonds missed duplicating this feat by one strikeout in 2004).
"Big Klu" enjoyed his most productive years from through , with home run totals of 40, 49, 47 and 35 while driving in over 100 baserunners in each, including a league-leading 141 RBIs in . He also hit .300 or better eight times. Kluszewski also led National League first basemen in fielding percentage five straight years, a major league record.
However, injuries began taking their toll; Kluszewski was limited to playing just four full seasons in his fifteen-year career. He spent his last four seasons switching teams. He was traded to the Pittsburgh Pirates before the season, and in August he was sent to the Chicago White Sox to give the team added punch. They eventually won the American League pennant and faced the National League champs, the Los Angeles Dodgers, in the World Series. In the first game at Chicago's Comiskey Park, Kluszewski slugged two home runs and drove in five in an 11-0 rout of the Dodgers. However, the Dodgers would win the next four out of five games and take the series with strong pitching that neutralized the White Sox' hitters — except for Kluszewski, who hit .391 with three home runs and ten RBIs, which tied Gil Hodges' mark set in the same series. About that time, Sox owner Bill Veeck introduced uniforms with players' names on the backs, above the numbers. Veeck deliberately spelled Ted's last name wrong.
When Major League Baseball decided to expand in , Kluszewski was one of the players left unprotected. He was selected by the Los Angeles Angels. Although hampered by back and leg problems, Kluszewski was the undisputed star of the Angels' first game ever, on April 11, against the Baltimore Orioles at Memorial Stadium, belting two home runs off the Orioles' Milt Pappas. Behind right-hander Eli Grba, the Angels defeated the Orioles 7-2. During his final season, Kluszewski hit .243 with 15 home runs and 39 RBIs in 107 games.
Post-retirement, Kluszewski was a hitting coach, most notably under Sparky Anderson with the Cincinnati Reds during their outstanding teams in the early and mid 1970's, which saw them win World Series championships in 1975 and 1976. In , he became the Reds' minor league hitting instructor, a position he held until , when he suffered a massive heart attack and underwent emergency bypass surgery. He retired afterward.
Ted Kluszewski died on March 29, in Cincinnati at age 63. His #18 was retired by the Reds on July 18, before a game against the visiting San Diego Padres at Cinergy Field. His widow, the former Eleanor Guckel, a 5'-2" (1.58 m) former softball pitcher (and, like her late husband, a southpaw), threw out the ceremonial first pitch. The Reds lost 2-1.