To provide a method for producing an azo pigment, which is excellent in color characteristics such as coloring power and hue and in durability such as lightfastness and ozone resistance, with good reproducibility and high efficiency.

The azo pigment represented by a formula (1) is produced by carrying out a coupling reaction between a diazonium compound with heterocyclic amine modified into diazonium and an intermediate compound of the object azo pigment in the presence of sulfuric acid. In the formula (1), Het is an aromatic heterocyclic ring such as a 5-amino-3-methyl-1,2,4-thiazolyl, and G is an atomic group constituting a 5-6 member heterocyclic ring.