In a globalising world, the international mobility of academics and researchers is important for their career. However, increasing migration of academics in the form of an academic brain drain is becoming a major challenge especially for Europe due to an ageing population. The issue of brain drain has been addressed usually through quantitative studies that fail to explore the in-depth reasons behind it, and present standard outcomes. Through a synthesis of qualitative literature over two decades (2000-2020), this paper presents a new perspective of the root causes of academic brain drain in Europe. After careful examination of the qualitative literature, five factors have been found to be responsible for the outflow of human capital. These include: (1) attractive salaries outside Europe; (2) short-term fixed contracts for early career researchers; (3) unfair recruitment procedures; (4) attractive migration policies and (5) the indirect role played by internationalisation policies to encourage permanent mobility.