He played in Major League Baseball (MLB) for the Los Angeles Dodgers, Kansas City Royals, Cincinnati Reds, Milwaukee Brewers and St. Louis Cardinals.

As a teenager, Broxton stood 6 feet 4 inches (1.93 m) tall, weighed 250 pounds (110 kg) and was athletic enough to dunk a basketball with two hands.

Broxton made his MLB debut on July 29, 2005, against the St. Louis Cardinals, pitching one inning in relief, allowing one run, and striking out two.

[3] After gaining the confidence of manager Grady Little, Broxton became Takashi Saito's primary setup man, and the team's backup closer.

Broxton had an excellent first half of the season and was selected to the 2010 Major League Baseball All-Star Game, in which he recorded the save.

However, he faded in the second half, beginning with a blown save against the New York Yankees in which he threw 48 pitches and allowed 4 runs on 4 hits and 2 walks.

In somewhat of a repeat performance against the Phillies, he blew another 4-run lead on August 12, as this time it was Carlos Ruiz delivering the 2-run walk-off hit.

Broxton returned to the closer role at the start of the 2011 season and appeared in 14 games in March and April, with a 5.68 ERA and 7 saves.

[11] On April 11, 2012, Broxton tied a dubious record for a major-league pitcher by ending and losing a game on consecutive hits by pitch (HBP).

[12] The last time this happened was on September 2, 1966, when Stu Miller of the Baltimore Orioles hit Al Weis and Tommie Agee of the Chicago White Sox.

On the July 31, 2012, MLB non-waiver trade deadline, Broxton was dealt to the Cincinnati Reds in exchange for minor league pitchers J. C. Sulbaran and Donnie Joseph.

After closer Aroldis Chapman was hit in the head with a line drive on March 19, Broxton took over closing duties for the Reds to start the 2014 season.

[18] Broxton made his Cardinals debut on August 1 in a 6–2 loss to the Colorado Rockies, pitching one scoreless inning, and allowing no runners to reach base.