Four different crystals are presented in the present article that are derived from a novel yellow pyrazolyl azo pigment used for ink jet inks. This compound exhibits a good pigmentary performance in light and heat stability but rather poor in solvent fastness. X-ray structure analysis has been carried out in order to improve the present drawback from the structural point of view. The authors have unexpectedly isolated two kinds of five-coordinate bisazo Na complexes of the cis form (space group: C2/c). The formation of the Na complex is found to be caused by NaNO₂ used for the preparation of diazo components. Then, the authors tried to eliminate the sodium atom from the Na complex using hydrochloric acid in an attempt to develop a better pigment that assumes a trans configuration. The present Na-free compound in the trans form is found to crystallize in space group P-1 and is characterized by good solvent fastness in addition to the light and heat stability of the original title compound.