Compared with the band's debut self-titled album, Fat Mattress II was a commercial failure, not appearing in any major record charts. The album was described, in a review for music website allmusic, by critic Richie Unterberger as "similar to, but also inferior to, their debut." Unterberger went on to suggest that "The songs aren't even up to the debut's modest standard, however, and the lingering feeling is that of a tolerable but fairly anonymous '60s-turning-into-'70s band with a Transatlantic feel."[1]