Generally, organic and organometallic materials containing π-conjugated chains are considered as promising candidates for nonlinear optical applications. In this work, we report on the third order nonlinear optical response of π-conjugated azo-conjugated azo-iminopyridine photoactive ligands containing electron donating or electron accepting fragments in their structure. The nonlinear optical investigation is performed by means of the Z-scan technique well as the Maker Fringes Third Harmonic Generation technique employing a 30 ps mode-locked Nd-YVO4 laser with a repetition rate of 10 Hz.