<p>Research on left-wing authoritarianism (LWA) is still scarce in German-speaking countries as a reliable, culturally invariant, and valid self-report measure is currently missing. The present research aims at mitigating this gap by adapting the Left-Wing-Authoritarianism-Index (LWAI) from English and Spanish into German (LWAI-G). In the present research, we tested the psychometric properties and the measurement invariance of the LWAI-G across different German-speaking countries. Also, we investigated its validity. For these purposes, we applied the LWAI-G in a convenience sample from German-speaking countries (<i>N</i> = 388) and representative samples from Austria (<i>N</i> = 837), Germany (<i>N</i> = 2,048), and the German-speaking part of Switzerland (<i>N</i> = 826). The results of the present research provide initial and preliminary evidence that the shorter (i.e., the 12- and 13-item) versions of the LWAI-G may be used for the scientific investigation of LWA in Austria, Germany, and the German-speaking part of Switzerland. For these shorter versions of the LWAI-G, the expected first-order factor structure with three correlated LWA factors (antihierarchical aggression, anticonventionalism, and top-down censorship) emerged. These shorter versions also demonstrated to be invariant across the representative samples. The results regarding the validity of the LWAI-G are mixed which demonstrates the need for further theory-based research.</p>