Problem to be Solved An agent for ameliorating and/or preventing anemia, which is useful in the amelioration and/or prevention of cancerous anemia, and can improve the quality of life of a cancerous anemia patient without advancing cancer progression, is provided. Solution An agent for ameliorating and/or preventing cancerous anemia containing 5-aminolevulinic acid (ALA) or a derivative thereof, or a salt thereof is prepared. Preferably, a metal-containing compound such as sodium ferrous citrate is contained in these ALAs. As the above-mentioned ALAs, ALA； various esters such as ALA methylester, ALA ethylester, ALA propylester, ALA butylester, and ALA pentylester； and hydrochlorides, phosphates, and sulfates, and the like of these ALA esters can be preferably exemplified.
