The study deals with the leftist organization of young Hungarian intellectuals in Czechoslovakia between the two world wars. Based on newly disclosed diplomatic and police sources, the paper mainly focuses on the movement´s official judgement by the Hungarian state. Horthy´s conservative Hungary took a critical view on the movement from the very beginning. After Sarló´s reorientation toward Marxism, the country regarded the leaders of Sarló as enemies, and kept them under constant surveillance. The study based on source analysis, has an ambition to provide background information to the realistic assessment of Sarló´s short-term leftist and communist orientation. Hungary´s official distrust toward young people engaged in the movement was an important contributing factor to that too.