Polyazines (PAZs) are well known polymer materials, whose synthesis can be traced back to as early as 1891 when Curtius and Thun obtained the first PAZ as an insoluble microcrystalline material from the reaction between a diacetyl compound and an equimolar hydrazine hydrate. PAZs comprise the π-conjugated azine linkage, CN–NC, which is isoelectronic with the diene structure, CC–CC. When a π-conjugated dialdehyde or diketone compound reacts with an equimolar hydrazine, formation of PAZs with extended π-conjugation along the polymer main chain can be expected . Compared with their carbon counterparts, PAZs were found to be more air-stable and have interested researchers since the 1980's mainly as electrically conductive polymers. Some PAZs also showed interesting nonlinear optical phenomena.4 However, to the best of our knowledge, the charge transport characteristics and application as semiconductors in organic thin film transistors (OTFTs) of this class of conjugated polymers have not been reported. In this work we designed a model π-conjugated polyazine, PDBTAZ, which was conveniently synthesized by reacting a dialdehyde functionalized diketopyrrolopyrrole (DPP) compound with hydrazine, to demonstrate that PAZs are a potentially very useful class of semiconductor materials for OTFTs. Recently, there has been growing interest in single-component ambipolar OTFTs, since they can be used for low-cost CMOS-like logic circuits that have high reliability, high noise immunity, and low power dissipation.5 The single component ambipolar semiconductors can transport both holes and electrons by simply varying the operation conditions, i.e., gate–source and drain–source bias voltages. We found that PDBTAZ is a high-performance ambipolar semiconductor in organic thin film transistors (OTFTs).