A method for producing crystals of 5-aminolevulinic acid hydrochloride wherein, in carrying out adsorption of 5-aminolevulinic acid contained in a crude 5-aminolevulinic acid solution by a cation exchange resin and its subsequent desorption with an aqueous solution containing ammonium ion, a high purity 5-aminolevulinic acid aqueous solution is obtained using a change in electric conductivity or pH of the desorption liquid as the index, and chloride ion is added to the aqueous solution which is then mixed with an organic solvent.