The episode received generally positive reception. Alan Sepinwall and Matt Zoller Seitz of "The Star-Ledger" were complimentary towards "Grace, Replaced", writing that the episode "is a winner, packed with witty dialogue." Monica Collins of the "Boston Herald" said that the episode "is one of the best of the series so far". "The Dallas Morning News" writer Ed Bark noted that "Grace, Replaced" was "another energetic, generally amusing" episode. Bark, in regards to Jack and Karen, said that the two together "sometimes are almost more than the scenery can bear." Aaron Barnhart for "The Kansas City Star" called the episode riotous, and said that the show "with pop-culture jokes delivered at blistering speed, outsized performances from 'supporting' players Sean Hayes and Megan Mullally, and a camaraderie between platonic pals Eric McCormack and Debra Massing that would make even Plato blush." Ted Cox of the "Daily Herald" was less positive about the episode, reporting that this episode "looked like more of the same", recounting the show's past story lines, and past NBC programs. "Chicago Tribune"'s Steve Johnson opined that the episode "starts strong and then goes awry [... It's funny for a while [...] But then it takes it to a ludicrous level, selling out its own internal logic by conspiring to put Shannon and Messing into a ... catfight. At its best this series works a groove of pop-culture savvy; this visit from "The Three Stooges" by way of "Dynasty" will have you rolling your eyes in dismay."