To prepare for her role in the series, Claire Danes met with CIA officers. She also watched videos made by people with bipolar disorder and consulted with author Julie Fast who suffers from the same disorder.
Carrie's name was originally intended to be Claire. It was changed to Carrie when Claire Danes accepted the role.
Some viewers believed Claire Danes portrayal of a bipolar sufferer was too realistic to be acting and wrote to the broadcaster suggesting that she be given time off.
Some of the photographs that are interspersed over the course of the opening credits sequence are actual pictures of Claire Danes as a young girl.
Season 4 was shot entirely on location in South Africa. According to director/producer Lesli Linka Glatter, the hardest part was finding neighborhoods that would resemble American suburbia for the few scenes that took place around Carrie's sister's house.