NBC producer Jim Bigwood selected the warehouse at 10 Enterprise Avenue in Secaucus, New Jersey as the filming location for the series.

"[34] Similarly, a review in The Hollywood Reporter calls the show "just another hospital soap opera" and "a lethal cocktail of virtually every medical drama ever seen on TV".

[34][35][37][38] The show's writing has been criticized as "twisting itself into a pretzel to provide ironies,"[35] and a review by Maureen Ryan of the Chicago Tribune states that "all the characters are so thinly drawn.

"[37] On the positive side, in a review in The Daily Telegraph, Rachel Ray found the show "utterly enjoyable" and "marvelous television", while praising the "clicking pace, real-person dialogue, excellent writing, a fresh story line, and thoughtful acting".

Noting an effort by NBC to find a replacement for the former standout ER, David Hinckley, from the New York Daily News, favorably compared the two shows and stated that Mercy "comes the closest yet to capturing that chemistry."