The political transformations of 1956 signifi cantly increased the options of scientifi c trips to the West, and stimulated the exchange of personnel between national scientifi c institutions and their Western counterparts. However, on consenting to the development of scientifi c co-operation with foreign entities, the communist authorities were fearful of opening to scientists a new path of emigration from PRL (the People’s Republic of Poland). Therefore, they were intent on controlling scientifi c exchange as strictly as possible, sending abroad mainly the politically trustworthy researchers. Both tasks turned out to be unachievable, but despite that, emigration to Western countries associated with scientifi c journeys (grants or scholarships) was marginal in the period of PRL. Furthermore, statistics suggest that most of Polish scientists traveling abroad, did not treat their stays as an opportunity to fl ee communist Poland. The article states statistical data confirming these conclusions. The decision to emigrate was always individual, nonetheless it used to be taken in a concrete social/political context. Conditions in the PRL apparently favoured decisions to stay abroad. Therefore, the small number of “defections” of scientists during their stays in western countries, is yet more surprising. It may be partly explained by the fact that scientists willing to emigrate had other ways to accomplish their aim, such as tourist travels, as well as the legal emigration procedure.