After the publication of 'A Storm of Swords' in 2000, which contains the 'Red Wedding' chapter, George R.R. Martin received numerous complaints and even death threats from readers.
The episode title refers to the song written about Tywin Lannister's crushing victory over rebellious House Reyne of Castamere and House Tarbeck, mentioned in Second Sons (2013). The song thereby serves as a reminder of the fate awaiting those who cross the Lannisters.
'The Rains of Castamere' is the only episode where the end credits play in total silence.
Michelle Fairley had never read the books, and was told of her character's fate shortly after the filming of the first season. She saw the episode for the first time while doing commentary for the DVD. By the end, she and her co-star Richard Madden were both in tears.
The scene where Robb cradles the dead Talisa's head in his lap had to be re-shot several times. Oona Chaplin kept crying at the scene going on around her and couldn't keep her eyes open.