Paulo Ferreira signed for Chelsea from Portuguese giants FC Porto on June 22, 2004. The self-acclaimed Special One Jose Mourinho played a big role in him signing for Chelsea. Mourinho had influenced his signing for FC Porto two years earlier. Paulo Ferreira was one of two players to follow Mourinho from FC Porto to Chelsea alongside compatriot Ricardo Carvalho. The two players had won several titles with their compatriot Mourinho at FC Porto before leaving the club for Chelsea.
Paulo Ferreira had to wait for his third season as a Chelsea player before he scored his first goal for the club. His first Chelsea goal came against lower league opponents Colchester United in the fifth round of the FA Cup. He scored one of the goals in a 3-1 win at home as Chelsea booked their place in the FA Cup quarterfinals. In that same third season, he lost his place as the first choice right-back to the likes of Dutchman Khalid Boulahrouz and then midfielders Geremi of Cameroon and LassanaDiarra of France. He was able to play in the 2007 FA Cup final clash with Manchester United. Ferreira played the whole game as Chelsea needed extra time to beat Manchester United 1-0 on May 19, 2007 in what was the first game played at the new Wembley Stadium.
In the 2007/08 season, he played second fiddle to Brazilian JulianoBelletti and Ghanaian Michael Essien at right-back. He penned a new five-year deal with the Blues on February 18, 2008. The arrival of compatriot Deco in the summer of 2008 prompted him to change his shirt number from 20 to 19.
Paulo Ferreira was at Chelsea for nine years until he retired in 2013 after 217 games for the club.