He was originally signed as third choice behind Petr Čech and Carlo Cudicini,[10] but was handed a run in the first team after they both sustained injuries in a game against Reading on 14 October 2006.

[14] Čech's return to fitness in February 2007 saw him lose his place in the team, and was an unused substitute in the Football League Cup final win over Arsenal.

[22] On 26 September 2009, when Čech was red carded against Wigan Athletic after a tackle on Hugo Rodallega, Hilário came on for Florent Malouda and conceded two goals in a 3–1 away loss.

[24] Hilário made his first appearance of 2010 after coming off the bench for an injured Čech in the second half of Chelsea's 2–1 loss at Inter Milan in the first leg of the Champions League round of 16, conceding no goals in about 30 minutes.

[25] He added another in the Premier League, this time against Manchester City, conceding braces from Craig Bellamy and Carlos Tevez in their first home defeat of the 2009–10 season (4–2),[26] although his side eventually won the championship.

[28] Following the appointment of countryman André Villas-Boas as manager[29] and the knee injury suffered by Čech in pre-season, he was propelled to the starting line-up over Ross Turnbull, appearing in two games and conceding twice in as many home wins.

[35] Hilário received his first call-up for Portugal in November 2009, at the age of 34, as backup to Eduardo for the 2010 FIFA World Cup qualifying matches against Bosnia and Herzegovina,[36][37] a role for which Beto, Daniel Fernandes, José Moreira and Rui Patrício were also tried.