James Hibberd of Entertainment Weekly wrote, "[the episode] was an intense rousing hour of heroism and heartbreak that set a new bar for what this show – and TV – can do." Another positive review came from Terri Schwartz of Zap2it.com, who wrote, "As the most expensive episode of the series, the Battle at Castle Black felt like an equivalent of The Lord of the Rings: The Two Towers Battle of Helm's Deep." David Malitz of The Washington Post was more negative about the episode, writing, "Aside from the major moment with Jon Snow and Ygritte it was hard to feel too emotionally invested in anything that happened. And as visually exciting as it was to watch everything unfold, the ending was surprisingly unfulfilling."
