This article explores the intersection of Cold War geopolitics, cultural psychiatry, and migration in Taiwan from the mid-1940s to the 1970s. Building on recent scholarship in cultural psychiatry and Cold War science, it examines how geopolitical tensions shaped psychiatric knowledge production in East Asia. Focusing on the psychological and social impact of the 1949 mass migration, when over a million Chinese immigrants arrived in Taiwan, alongside the clinical and academic work of Taiwanese psychiatrists, the study highlights how migration and societal upheaval became central research concerns. Operating under the authoritarian Kuomintang regime and within the constraints and opportunities of international politics, Taiwanese psychiatrists – most of whom were native-born with colonial backgrounds – drew on intellectual traditions from imperial Japan, fascist Germany, and the Cold War Western bloc. Navigating both global psychiatric discourses and local concerns, they positioned themselves as key contributors to the international development of psychiatric research. While their portrayals of Chinese character structure and family dynamics sometimes reflected essentialist views, their work also demonstrated a nuanced awareness of historical change and contemporary realities during a period of intense political repression and uncertainty. By analysing archival sources and medical texts, this article illuminates the complex interplay between geopolitics and psychiatric knowledge production in Cold War Taiwan.