For an edition which saw Kerry Katona, Bobby Sabel and Sally Bercow put up for eviction, the Channel 5 reality show averaged 3.22m (14.8%) in the 9pm hour, a drop of nearly 2m on Thursday's premiere night.
While Celebrity Big Brother experienced an even greater dip at the start of its last series on Channel 4 in 2010, the broadcaster will be hoping the show steadies, as channel executive Richard Desmond recently stated that he did not expect the show to fall under 3m.
Gavin Henson-headed reality show The Bachelor followed CBB with a respectable 1.33m (7.8%) in the 10pm hour, then Celebrity Big Brother's Bit on the Side with Emma Willis had 676k (6.4%) from 11pm.
BBC One was the only channel ahead of Channel 5 in the 9pm hour, as My Family and Miranda dipped to 3.7m (17%) and 3.66m (16.9%), while ITV1's Somebody's Daughter, Somebody's Son could only muster 2.43m (11.1%) and 136k on +1.
Channel 4's lineup suffered, as 8 Out of 10 Cats and Chris Moyles' Quiz Night took 1.12m (5.1%) at 9pm (+1: 281k) and 958k (4.7%) at 9.45pm (+1: 276k).
Come Dine with Me, meanwhile, showed its resilience with 1.31m (6.1%) at 8pm (+1: 148k) against the opening Gadget Show episode on 5, which interested 968k (4.5%).
Over on BBC Two, Gardeners' World logged 1.77m (8.1%) at 8.30pm, then India on Four Wheels captured 2.2m (10.1%) in the 9pm hour and The Rob Brydon Show entertained 1.56m (8.2%) at 10pm.
Overall, ITV1 predictably led primetime with 19.4% (+1: 0.5%) against BBC One's 19.2%. Channel 5 claimed third place with 8.4%, ahead of BBC Two's 6.9% and Channel 4's 5% (0.8%).
BARB ratings data supplied by Attentional