An average of 6.2 million viewers tuned in to watch the launch of the eighth series of Channel 4's Big Brother, according to overnight figures.
Some of the housemates were booed as they entered the house
Audience numbers were down by 800,000 compared with 7 million viewers for the start of the seventh series in 2006.
Following the end of ITV's British Soap Awards and BBC One's The Apprentice, the audience peaked at 8 million.
It is the first time an all-female house has launched the show, but a male housemate will join them shortly.
Viewing figures were well above average for the C4 time slot, with the reality show drawing 26 per cent of available viewers.
Channel 4's commissioning editor for Big Brother, Angela Jain, said: "This heralds a fantastic start to Big Brother."
The show opened with an official apology, ordered by Ofcom, over C4's handling of the race row involving celebrity contestants Jade Goody, Danielle Lloyd and Jo O'Meara and their treatment of Bollywood actress Shilpa Shetty.
House rules for this series have been updated to warn against bullying and to make clear that offensive remarks on the grounds of race, religion or sexuality are unacceptable.
Carole received the biggest cheer of the night from waiting crowds
The 11 contestants include the first set of twins ever to enter the house, a member of the Women's Institute and a Victoria Beckham wannabe.
Charley, an unemployed former lap dancer, was greeted with boos and chants of "get a job" by the crowd as she arrived at the house, at Elstree Studios in Hertfordshire.
Political protester Carole received the loudest cheer of the night.
A single man is expected to enter the house on Friday to join the contest for the £100,000 prize.
It is rumoured that the female contestants will choose from three possible contenders.