"Lost and found" debuted at number six on the US "Billboard" 200, selling 98,000 copies in its first week. The album reached number four on the "Billboard" Top R&B/Hip-Hop Albums chart. Outside of the US, it reached number 15 on the UK Albums Chart, and also reached the top 20 in Germany. Media response to "Lost and Found" was mixed; aggregating website Metacritic reports a normalized rating of 50, based on 10 critical reviews, indicating "Mixed or average reviews". "Entertainment Weekly" awarded the album a B+ rating, describing it as "packed with the sort of undeniable pleasures only the most churlish thug could deny". Andy Kellman of AllMusic described it as "an entertaining and thoughtful album for young kids and their parents to listen to and talk about", while PopMatters' Mike Schiller praised "Lost and Found" as a return to form for Smith, but noted that his audience had likely dwindled by the time of the album's release. Christian Hoard of "Rolling Stone" noted that while the album features "plenty of up-to-date beats", "Lost and Found" is let down by the fact that Smith does not have "a commanding presence" on many of the songs, which Hoard claimed made the rapper "utterly unconvincing" and "fast running out of steam". A review in "The Guardian" simply concluded that "[Smith's] decision to stray from his usual blend of impish party tunes and extended jingles for the latest summer blockbuster constitutes one of the most ill-advised career moves since MC Hammer went gangsta". Greg Tate of "The Village Voice" dubbed "Lost and Found" "the lamest album that'll be released this year", describing Smith's style as "imitation hip-hop". Personnel credits adapted from liner notes.