4-Amino-1-(and 2-)methyl-1,2,3-triazole-5-carbonitrile were made by acidic hydrolysis of 4-dimethylaminomethyleneamino-1-(and 2-)methyl-1,2,3-triazole-5-carbonitrile. These amino-nitriles, and also their known 3-methyl- and 3-benzyl-analogues, were hydrogenated to 4-amino-5-aminomethyl-1-methyl-1,2,3-triazole (1a) and its 2- and 3-methyl- and 3-benzyl analogues [(3a), (4a), and (4b), respectively]. Bis-(4-amino-3-benzyl-1,2,3-triazol-5-ylmethyl)amine (5), was obtained as a by-product. Nine N-acyl derivatives are described in which a formyl, acetyl, ethoxycarbonyl, (ethylthio)carbonyl, or ethoxalyl group substitutes the aminomethyl system, also four derivatives in which both amino-groups are monoacylated.N.m.r., u.v., and i.r. data and ionization constants are reported and discussed. An estimate of the electron-attracting strength of the 1,2,3-triazole nucleus places it between benzene and pyrazine.