Life in Cold Blood is a BBC nature documentary series written and presented by David Attenborough, first broadcast in the United Kingdom from 4 February 2008 on BBC One.A study of the evolution and habits of amphibians and reptiles, it is the sixth and last of Attenborough's specialised surveys following his major trilogy that began with Life on Earth, hence a ninth part for the eight series in The Life Collection.

The series comprises five 50-minute programmes, each one followed by Under the Skin, a 10-minute section that features Attenborough interviewing the scientists whose work has led to the sequences included in the main programme. It also examines the challenges faced by the crew and reveals some of the techniques used to film the series.The series is a BBC Animal Planet and Open University co-production. The executive producer is Sara Ford and the series producer is Miles Barton. The Under the Skin segments were produced by James Brickell in collaboration with the Open University. The score for the main films was composed by David Poore and Ben Salisbury, whilst the music for Under the Skin was written and performed by Tony Briscoe.

The series won the 2009 BAFTA Television Award in the Specialist Factual category. Within David Attenborough's 'Life' series, it is preceded by Life in the Undergrowth (2005).