On putting pen to a five-and-a-half year contract he become the third Brazilian in the squad, linking up with former Benfica team-mate Ramires and fellow defender Alex.
A 6ft 2in centre-back who can cover at either left- or right-back, he is renowned for his skill on the ball as much as his defensive ability.
After signing for Chelsea, he outlined his determination to nail down a regular place in the side, and took the previously unclaimed number 4 shirt, last worn by Claude Makelele.
He won plenty of plaudits for his early showings, and although he conceded a late penalty on his first start against Fulham, saved by Petr Cech, he went on to win the man of the match award.
Ineligible for the Champions League, he retained his place in the Premier League side until a goal conceded in the opening seconds at Old Trafford torpedoed Chelsea's title chances and Carlo Ancelotti left the Brazilian out of the remaining games.
He had earlier scored against United at Stamford Bridge, and headed home against Manchester City in the Premier League to keep our title hopes alive.
A knee injury following international duty meant he started the 2011/12 campaign out of the side but he returned in mid-September and duly found the scoresheet again, this time curling home from the edge of the area against Bayer Leverkusen on his Chelsea Champions League debut.
After an up and down first half of the campaign, he slowly settled down and adjusted to the English game, making over 30 appearances alongside various centre-back partners as injuries to others took their toll.
David started 15 consecutive games over the Christmas and new year period and, as Easter approached, even started to win round some of his harshest media critics with an unusual blend of no-nonsense defending and samba style. His penchant for goalscoring hadn't lessened either, as home league strikes against United and Bolton testify.
The Brazilian defender was superb in the 4-1 Champions League win against Napoli, but after injuring himself in the FA Cup semi-final win against Tottenham, he missed a number of crucial matches as the season drew to a close, including the FA Cup Final against Liverpool.
However, after an intense rehabilitation programme, David Luiz was deemed fit to play against Bayern Munich in the Champions League Final, where he completed the full 120 minutes and scored our second penalty in the shoot-out.
David Luiz was a regular in the side as we began the 2012/13 season in some style, and underlined his commitment to the club by signing a new five-year contract minutes after the final whistle had sounded on our 1-0 win over Stoke City.
He scored his first goal of the season with a stunning free-kick in our 4-0 Champions League win against FC Nordsjaelland, while also netting from the penalty spot in the 5-4 Capital One Cup win against Manchester United at Stamford Bridge.
In April, David Luiz netted two contenders for goal of the season in quick succession. A last-gasp winner in our Europa League semi-final against Basel was sandwiched in between a 35-yard thunderbolt at Craven Cottage against Fulham and a beautiful, left-footed curling effort, hit first time, in the return leg with Basel.
A long campaign that had seen us competing in seven different competitions hadn't always gone our way, with the Brazilian visibly upset as we fell to his native Corinthians in the Club World Cup final in Japan. The season ended on a positive note, however, with David Luiz starting in the Europa League final victory against his old side Benfica. His tally of 57 appearances by the season's end was the most in his career to date.
His current campaign has been disrupted by injury at various points, but the Brazilian has played a crucial part in some of our most memorable performances. Deployed in midfield for the home game against Liverpool, he shone as we came from behind to win 2-1, and it was his partnership with Nemanja Matic, again in midfield, which enabled us to nullify the Manchester City threat as we became the first team to win at the Etihad in the Premier League this season.
The duo also combined effectively as we beat Arsenal 6-0 at Stamford Bridge.
Twenty-three years old when he signed on deadline day in January 2011, David Luiz was born in Sao Paulo and began his career with Esporte Clube Vitoria in Bahia where he made 47 appearances.
He switched to Benfica, initially on loan, in January 2007 before making the move permanent that summer.
In total he made 82 league appearances for the Lisbon club missing just one game in the 2009/10 season as they wrapped up a first league title in five years. Uefa.com voted him the Portuguese League's Player of the Year.
David Luiz, who made his Brazil debut against the United States during the 2009/10 season, had earlier represented his country at the 2007 Under-20 World Cup,
He was in the Brazil squad that contested the Copa America in July 2011, and returned to the squad for the September internationals despite not having featured for Chelsea.
He has been a regular in the national side since his move to west London, and captained them for the first time in September 2012, in successive friendlies against South Africa and China. He also skippered the five-time World Cup winners during their friendly defeat against England at Wembley in February 2013.
David Luiz was an ever-present throughout Brazil's successful Confederations Cup campaign in June 2013. The hosts topped their group before overcoming Uruguay in the semi-final and Spain in the final.