Thick as a Brick was originally scheduled for release on 25 February 1972. Following production problems relating to the
1972 miners' strike, it was held back a week to 3 March. where it was certified Gold. Contemporary reviews were mixed.
Chris Welch of
Melody Maker praised the musicianship of the band and Anderson's flute playing, writing also that "the joke at the expense of a local newspaper wears thin rather rapidly, but should not detract from the obvious amount of thought and work that has gone into the production of
Thick"; he described the music as a creative effort where "the ideas flow in super abundance" but that "needs time to absorb" and "heard out of context of their highly visual stage act ... does not have such immediate appeal".
Tony Tyler in his review for
New Musical Express generally appreciated the construction of the suites and the arrangements, but he had doubts about the album's possible success. He called
Thick as a Brick "Jethro Tull's own stand-or-fall epic after the lines of
Tommy" and "an assault on the mediocrity and harshness of lower-middle-class existence in '70s Britain". Ben Gerson in
Rolling Stone magazine called
Thick as a Brick "one of rock's most sophisticated and ground-breaking products". Going further, the reviewer stated: "Martin Barre's guitar and John Evan's keyboards especially shine, and Ian's singing is no longer abrasive. Whether or not
Thick As A Brick is an isolated experiment, it is nice to know that someone in rock has ambitions beyond the four- or five-minute conventional track, and has the intelligence to carry out his intentions, in all their intricacy, with considerable grace."
Rolling Stone's Alan Niester gave it 2 out of 5 stars in
The Rolling Stone Record Guide, judging it had "relatively undifferentiated movements".
Village Voice critic
Robert Christgau disliked the album, calling it "the usual shit" from the band: "rock (getting heavier), folk (getting feyer), classical (getting schlockier), flute (getting better because it has no choice)". Paul Stump's
History of Progressive Rock commented of the album, "The 'concept', a somewhat self-conscious and mannered lionization of individual genius ... against caricatured bourgeois Philistinism, scarcely sees the light of day through the thickets of Anderson's imagery, but this doesn't detract from what, in hindsight, is quite a respectable, if periodically water-treading, stab at advanced extensional technique." In 2014,
Prog magazine listed
Thick as a Brick at number 5 in the list "The 100 Greatest Prog Albums of All Time", voted for by its readers.
Rolling Stone listed the album at number 7 in their "Top 50 Prog Albums of All Time".
Rush's
Geddy Lee has said
Thick as a Brick is one of his favourite albums, as has
Iron Maiden's
Steve Harris. In 2023, John Cunningham of
WhatCulture wrote: "The greatest parody of prog rock ever recorded, Jethro Tull's 1972 LP was a refreshing prank in a mostly serious and complicated music scene." == Reissues ==