Maldonado raced in Italian and European Formula Renault from 2003, winning the Italian Formula Renault title in 2004 with eight wins from seventeen starts. He progressed to the Formula Renault 3.5 Series in 2006, finishing third overall despite a disqualification from first place at Misano for a technical infringement that, had it been retained, would have given him the championship. A four-race ban for dangerous driving at Monaco during his World Series by Renault appearances in 2005 hinted at the controversies to come.
Maldonado entered the GP2 Series with Trident Racing in 2007, taking his first victory at Monaco in only his fourth race. A broken collarbone during training ended his season early. He moved to Piquet Sports in 2008, scoring four podiums in the final six rounds including a win at Spa, and to ART Grand Prix in 2009 alongside champion Nico Hülkenberg, finishing sixth overall.
With Rapax in 2010 Maldonado delivered the defining performance of his junior career, winning six consecutive feature races from Istanbul Park to Spa on his way to the championship. He accumulated ten race victories in total that season, a series record at the time, and clinched the title at the penultimate round at Monza, finishing sixteen points ahead of Barwa Addax's Sergio Pérez. Rapax also won the Teams' Championship.
Maldonado joined Williams for 2011, bringing significant sponsorship from PDVSA, the Venezuelan state oil company. His first season established his pattern: competitive qualifying pace paired with race incidents and penalties. He scored his first championship point with tenth place at the Belgian Grand Prix.
The 2012 season contained his career high point. At the Spanish Grand Prix, Maldonado qualified second alongside Lewis Hamilton on the front row; Hamilton was subsequently excluded from qualifying for insufficient fuel, handing Maldonado pole. He led after the second round of pit stops and held off Fernando Alonso and Kimi Räikkönen to win, becoming the first Venezuelan to take an F1 podium. A fire in the Williams pit during post-race celebrations saw Maldonado rescue his cousin from the flames. However, the same season brought fourteen penalties — the most of any driver — and 38 total grid-penalty places across the year.
He joined Lotus for 2014 and 2015, partnering Romain Grosjean. His only points finish across two seasons at Lotus came ninth in the 2014 United States Grand Prix. He accumulated penalty points at a high rate and was involved in incidents at virtually every race weekend. Commentators referred to him as "Crashtor". His contract for 2016 was terminated when Renault acquired Lotus and his PDVSA backing arrangements collapsed; Kevin Magnussen replaced him.
Maldonado served as a Pirelli test driver in 2017. He returned to racing with DragonSpeed in the FIA World Endurance Championship LMP2 class for the 2018–19 WEC superseason, finishing third in class. In 2019 he took LMP2 class honours at the 24 Hours of Daytona with DragonSpeed alongside Roberto González, Sebastián Saavedra, and Ryan Cullen.
Maldonado remains one of the most contradictory figures in recent motorsport history: a genuine GP2 champion with a dominant 2010 season and an authentic Formula One race winner in 2012, yet also one of the most penalised and accident-prone drivers in F1's modern era. His 2012 Spanish Grand Prix victory is the last win recorded by a Williams driver as of 2025.