Dessens was signed as an amateur free agent by the Pittsburgh Pirates in 1993. He made his major league debut with the Pirates in 1996 and pitched with them until1998. The Pirates released him at the end of spring training in 1999. He pitched that season for the Yomiuri Giants of the Nippon Professional Baseball League in Japan.
Dessens returned to the major leagues in 2000 with the Cincinnati Reds and pitched for them for three seasons.
During the 2002–03 offseason, Dessens was involved in a four-team trade that sent him to the Arizona Diamondbacks.
Dessens stayed with the Diamondbacks until August 2004, when the Los Angeles Dodgers acquired him for a minor leaguer to bolster their bullpen for the stretch run. That October, Dessens pitched in the postseason for the first and, to date, last time, appearing in one game during the Dodgers' Division Series loss to the St. Louis Cardinals.
Dessens pitched one more season for the Dodgers, then became a free agent in the offseason.
Prior to the 2006 season, Dessens signed with the Kansas City Royals. In July, the Dodgers reacquired Dessens from the Royals for pitcher Odalis Pérez and two minor leaguers, again to bolster their bullpen. While the Dodgers did win the wild card that season, Dessens did not appear as the Dodgers were swept in the Division Series to the New York Mets.
In March 2007, Dessens was traded from the Dodgers to the Milwaukee Brewers for reserve outfielder Brady Clark and cash. In early August he was released by the Brewers, but a few days later he signed a minor league deal with the Colorado Rockies. He started 5 games for the Rockies, going 1–1 with a 7.58 ERA. He became a free agent at the end of the season.
In January 2008, Dessens signed a minor league contract with the Pittsburgh Pirates, but was released during spring training. He then spent most of the 2008 season in the Mexican League with the Diablos Rojos del México. After pitching (and winning) the final game of the league championship against the Sultanes de Monterrey, he signed a major league contract with the Atlanta Braves in August. After the season, Dessens again became a free agent.
In February 2009, Dessens signed a minor league deal with the New York Mets. Dessens made his Mets debut on June 23, 2009 against the St. Louis Cardinals. He was designated for assignment on July 30. He had his contract purchased on August 6, 2009, when Jon Niese was placed on the 60-Day disabled list.
In December 2009, Dessens signed a minor league contract with the New York Mets for the 2010 season.
On February 8, 2011, it was reported that Dessens had signed a minor league deal with the San Francisco Giants that included an invitation to spring training.However, on February 14, it was reported that the deal fell through.
He is currently an assistant pitching coach for the Arizona League Reds.
