Three tracks released on singles in 1969 appear on album for the first time here: "Hot Fun in the Summertime", "Everybody Is a Star", and "Thank You (Falettinme Be Mice Elf Agin)".

Greatest Hits was certified quintuple platinum by the Recording Industry Association of America (RIAA), having shipped five million copies in the United States.

Prior to the release of this album in November 1970 the musicians were not able to make stereo mixes of "Hot Fun in the Summertime", "Everybody is a Star" and "Thank You (Falettinme Be Mice Elf Agin)".

"[11] In the March 1971 edition of Ebony, Phyl Garland hailed it as among the best recent "best of" LPs and "a true bonanza" of psychedelic soul, recommended especially for fans of the genre.

He also asserted that the music's flashy stereo separations, vocal sounds, and register alterations made Greatest Hits "the toughest commercial experiments in rock and roll history".

Of Greatest Hits in general, he called it "one of the best compilation rock/pop/funk recordings ever" and "chock full of brilliant, influential, and too-often-overlooked pop greatness" that will make listeners "dance and smile".

[14] In his review of the 2007 reissue, Andrew Gilstrap from PopMatters said that, although it is not comprehensive, the "slapped-together feel" may be "part of what makes Greatest Hits work so well, as if it was put together with the same freewheeling spirit that characterized the band.