AllMusic gave the album a positive review, stating "With its technical brilliance, musical complexities, and aggressive overtones,
Undertow not only paved the way for several bands to break through to the mainstream adolescent mall-rage demographic, it also proved that metal could be simultaneously intelligent, emotional, and brutal." In
Entertainment Weeklys review of the album,
David Browne said "Like many of its brethren in the alternative-metal corps—
Alice in Chains,
Stone Temple Pilots, and
Helmet—Tool can crunch and lumber about with the best of them. What put this L.A. band a notch above the rest are better songs (with actual verses, choruses, and hooks-check out the terrific "Prison Sex") and the hints of vulnerability in singer
Maynard James Keenan's voice". In a
Dotdash bibliographical article of the band, reviewer Tim Grierson called the album the "Essential Tool Album" and stated "It may be impossible to describe the impact that
Undertow had at the time of its release in 1993. Searching, angry, liberating and scary, Tool's full-length debut emerged during a period in rock music when Seattle bands like
Nirvana and
Pearl Jam were expressing alienation through grunge riffs, inspiring lots of copycat artists.
Undertow expressed alienation, too, but the album's imposing waves of misery and dread seemed to come from an entirely different planet than grunge, providing a startling counterpoint to the trendy sounds of the era". A less positive review came from
Select writer Andrew Perry, who said "[B]ereft of the irony, danger and maverick punkiness of grunge's finest, Tool ultimately will only help Alice In Chains reassert the trad metal market. Which really isn't what we deserve." ==Accolades==