This species is only known from a couple of collections and there is insufficient information on its range, population trends and threats to assess it. Therefore, Yucca declinata is here listed as Data Deficient. This species would benefit from more research to document more specimens, establish the extent of its range and threats affecting it.

Yucca declinata is endemic to the state of Sonora in Mexico (Felger et al. 2001).

Yucca declinata is known from only a couple of collections from which it is inferred the species is not abundant. It grows in an areas were many similar species co-occur and probably is often mistaken. The population trend and range of the species are unknown.

Yucca declinata favours rocky, volcanic, or limestone hills and valleys with clay soils (Felger et al. 2001). Yucca declinata is also present in open oak woodland and is typically found at an elevation between 750-1,230 m asl (Felger et al. 2001).

Little is known about Yucca declinata, it is found in an area that have been subject to cattle ranching for a long time, however it is unknown how and if this threat is negatively impacting the species.

The fruits of Yucca declinata are eaten by locals and are called dátiles (Gentry 1972, Laferriere 1995). It is not found in trade.

This species may be present in the private reserve Reserva de Jaguares Sierra Los Pavos but this needs to be confirmed. Seeds have been deposited in seed bank at Desert Botanical Garden, Phoenix Arizona.