Reviews for the album were generally favorable. Rob Sheffield of Rolling Stone gave the album four out of five stars, saying, "Why anybody would choose to spend their life without a copy of This Is Not a Test! is a mystery."  Dan Martin of NME gave the album eight out of ten stars, saying the album was "all about the beats" and "not a right lot else", adding it was "Missy's most uncompromising work yet".  Nick Catucci of Blender gave the album three out of five stars, saying the album "lacks feeling" and asked, "besides beats, what else does she care about?"  John Bush of AllMusic gave the album three out of five stars, saying the album "is an effective argument for song-by-song downloads."  This Is Not a Test! placed on Slant Magazine 's list of best albums of the 2000s at number 87.