The name Carnegia gigantea is used by Kartesz (1994) in his Synthesis of the North America Flora, however, it appears that the genus name represents a misspelling, as Index Nominum Genericorum indicates that Carnegia as a genus is placed in another family, other than Cactaceae (Chrsostomataceae).  The spelling of the genus as applied to the cactus species is Carnegiea (Carnegiea gigantea) as per Index Nominum Genericorum.  All other sources consulted regarding this cactus spell the genus 'Carnegiea' after Andrew Carnegie.

Carnegiea gigantea has a wide range. Even though there is a decrease in the population, this species is still locally abundant and the observed decrease is not sufficient to trigger a threat listing. Hence, the species is listed as Least Concern.

The species occurs in the Mexican state of Sonora and in the Unites States in Arizona and California (Hunt et al. 2006), at elevations of 0 to 1,370 m asl (Paredes et al. 2000).

Carnegiea gigantea is locally abundant; however there is a decline over most of its range.

The species grows on well-drained land, on hillsides and on plains in thorn scrub and desert scrub (Paredes et al. 2000).

In Mexico, Carnegiea gigantea is primarily threatened by changes in land use for cattle ranching.  In the Unites States, this species is primarily threatened by urbanization. Saguaros are also threatened by collection from the wild, including indiscriminate and illegal trade (Paredes et al. 2000). There is a high demand for Saguaro ribs, the internal woody frame of this cactus species, that leads to over-collection. The species is threatened by competition from the invasive buffelgrass (Pennisetum ciliare) and from the increased frequency of fires associated with buffelgrass.

Historically, this species has been used in a variety of ways including: material for building walls, using the fruit to make wine, for medicinal purposes, and for rituals. Today, the species is collected from wild populations and used to make furniture and handicrafts (Paredes et al. 2000) and as ornamental plants.

The species occurs within protected areas in Mexico and the United States, for example Saguaro National Park. This species is legally protected in Mexico by the national list of species at risk of extinction, NOM-059-SEMARNAT-2010, where it is listed under category “threatened” (A; SEMARNAT 2010).