The contribution presents an overview and characteristics of the single phases of a long term cooperation of outstanding ethnographic museum and academic scientific institution. The centre of the interest lies on the 1950s and 1970s. The author is an ethnographer emeritus and museologist emeritus, the former director of the Slovak National Museum in Martin (in the years 1963-1975). He shows the social, political, scientific, practical, institutional and personal levels of the mutual working relationship with the Institute of Ethnology (former Ethnographic Institute) of the Slovak Academy of Sciences. The results and the form of this cooperation are presented as the factors of scientific and social reliability of ethnology in Slovakia.