The men of the royal family were all dressed in their finest tuxedos and laughing with Sir David outside the venue.
Throughout the evening, Prince William and Prince Harry mingled with other high profile celebrities including David Beckham and Harry's rumoured ex-girlfriend, singer Ellie Goulding.
Sir David Attenborough's eight-part series on Netflix will showcase the planet's most endangered species and fragile habitats, and is available on the streaming service on Friday.