Worsham grew up in a racing family based in Southern California. His father ran a nitro Funny Car operation, and Del made his first professional start at the final race of the 1990 NHRA season in Pomona, California. Racing out of his family's team from the beginning, he developed quickly in the competitive Funny Car ranks, establishing himself as one of the sport's most consistent performers through the 1990s and 2000s.
Seven races into the 1991 season, at age 21, Worsham won the Southern Nationals in Atlanta, Georgia — becoming the youngest driver ever to win a Funny Car event at that time. He followed that victory with another win at the Summernationals in Englishtown, New Jersey, later that summer. At the season's end, Worsham finished sixth in the Funny Car points standings and was named the NHRA Rookie of the Year. His 1992 campaign produced no wins but showed continued development, with a fourth-place finish in the points standings.
Worsham competed primarily in Funny Car from 1991 through 2010, accumulating 25 victories in that category. During the 1993–1995 period he split time between Funny Car and Top Fuel, recording a top speed of 300.20 mph in Top Fuel competition and gaining valuable experience across the nitro categories.
His best Funny Car season came in 2004, when he qualified for all 23 events, reached the semifinals 13 times, won five races — a career best at that point — and posted 41 elimination-round wins. He finished second in the NHRA POWERade Championship Point Standings that year, 297 points behind champion John Force. The 2004 campaign represented the peak of four consecutive top-four point finishes between 2001 and 2004.
During 2001 and 2002 he finished third in the standings in back-to-back seasons, winning four races each year and maintaining 35 elimination-round victories both campaigns. He qualified for the championship rounds at every Funny Car event in 2001, was one of only three drivers to accomplish that in 2003, and ran a consecutive-qualifying streak of 98 events that stretched from 2002 until it ended at Topeka, Kansas, in 2006.
In late 2008, Worsham was named the new driver of the Al-Anabi Racing Funny Car. Joining the Alan Johnson-led team in 2009, he won three races in his final season before the team made the shift to Top Fuel for 2011. His 2010 Funny Car season, which again saw him qualify for every event and reach the playoffs, was his last in the category for several years.
When Al-Anabi Racing transitioned to Top Fuel for 2011, Worsham returned to a class he had not competed in since 1995. The results were immediate. He won his first Top Fuel event at the Gatornationals in Florida, defeating seven-time champion Tony Schumacher. He went on to win two more Top Fuel races that season and, on November 13, 2011, captured the NHRA Top Fuel championship at the Auto Club NHRA Finals in Pomona, California, over Spencer Massey.
Worsham holds two NHRA national championships. His 2011 Top Fuel title came after accumulating eight Top Fuel victories over the course of his career, while his 25 Funny Car victories were capped by the 2015 NHRA Mello Yello Championship in Funny Car, which he won while driving for Kalitta Motorsports. The Funny Car title made him one of history's rarest multi-class champions.
Following his 2011 championship, Worsham announced his retirement from driving and transitioned to the crew chief role at Kalitta Motorsports, leading the Tequila Patrón-sponsored Funny Car driven by Alexis DeJoria. In late 2012 he returned to the cockpit for Kalitta as the driver of the DHL Toyota Camry Funny Car, a role he held through 2016.
In late 2016, Worsham rejoined the family team — Worsham Racing — with Lucas Oil Products as a primary sponsor, returning to where his career had begun. By 2019 he was also serving as co-crew chief for Shawn Langdon's Global Electronics Funny Car entry within the Kalitta Motorsports organization, demonstrating his value on both sides of the pit wall.
Del Worsham's career exemplifies the dual expertise required to compete at the highest levels of NHRA nitro racing. With championships in both Top Fuel (2011) and Funny Car (2015), more than 33 career national event victories, and decades of consistent top-ten finishes, he ranks among the most accomplished all-around nitro racers of his era. His record as the youngest-ever Funny Car winner in 1991 held historical significance, and his seamless transitions between driving, crew chief duties, and family team leadership reflect a deep commitment to the sport across all dimensions.