The exact circumscription of the tribe has been subject to considerable change, particularly since molecular phylogenetic approaches have been used in determining classifications, and remains uncertain.

[1] Some species can grow to be over 15 m (50 ft) tall, like the saguaro (Carnegiea gigantea)[2] and Cephalocereus macrocephalus (syn.

Pachycereeae was a newly published taxon; Echinocereeae was an elevation of the subtribe Echinocereinae ("Echinocereanae") established by Britton and Rose in 1922.

[9] Genera placed at one time or another within the Echinocereeae (or Pachycereeae) fell within the "Core Cactoideae I" clade in the 2011 molecular phylogenetic study by Barcenas et al.[8] Possible phylogenetic relationships within this clade are shown in the cladogram below, based on Guerrero et al. (2019)[10] and revisions to the Hylocereeae in 2017 and 2020.

[11][12] Austrocactus, Corryocactus, Eulychnia Armatocereus, Leptocereus, Neoraimondia, Strophocactus (including Pseudoacanthocereus) Core Echinocereeae Hylocereeae "Core Echinocereeae" recovered in molecular phylogenetic analyses in 2005 and 2011 contains the following genera, often only in part compared to earlier generic circumscriptions.