In this letter, we present complementary tunneling field-effect transistors (CTFETs) based on strained Si with gate all around nanowire structures on a single chip. The main focus is to suppress the ambipolar behavior of the TFETs with a gate–drain underlap. Detailed device characterization and demonstration of a CTFET inverter show that the ambipolar current is successfully eliminated for both p- and n-devices. The CTFET inverter transfer characteristics indicate maximum separation of the high/low level with a sharp transition (high voltage gain) at a $V_{\mathrm{ dd}}$ down to 0.4 V. In addition, high noise margin levels of 40% of the applied $V_{\mathrm{ dd}}$ are obtained.