The Erasmus Programme for higher education students is supposed to play an important socio-economic role within Europe. Erasmus student mobility flows have reached a relevant level of two million since 1987, boosted in recent years by the enlargement of the programme to eastern countries. Thereafter, it seems that flows have staggered. In this context, the article analyses the determinants of Erasmus student mobility establishing relevant hypotheses, which arise from the migration theory and gravity models. A panel data set of bilateral flows for all the participating countries has been used in order to test the factors influencing these student flows. Country size, cost of living, distance, educational background, university quality, the host country language and climate are all found to be significant determinants. Results also reveal that there are other determinants, like a country's characteristics and time effects, which can affect mobility flows. Based on these findings, some general recommendations are put forward to enhance these flows.