Ethyl-, propyl-, and benzyl-guanidine nitrates were prepared from amine nitrates and calcium cyanamide or dicyandiamide. Carboxyalkylguanidines were made by condensing the corresponding amino acids with guanidine carbonate in aqueous medium. All the guanidine nitrates, except the benzyl derivative, were converted into the corresponding nitroguanidines by treatment with concentrated sulphuric acid. Esters and metal salts of 1-(α-carboxyalkyl)-2-nitroguanidines were also prepared.