Enjoying such a privileged family environment in science, education and research, it is not surprising that young Ulf would become a scientist, too, so he went to study Medicine at the Karolinska Institute in 1922. At Karolinska, he worked under Robin Fåhraeus in blood sedimentation and rheology and did research work on the pathophysiology of vasoconstriction. He presented his doctoral thesis in 1930, and was appointed as Assistant Professor in Pharmacology in the same year, with the support of G. Liljestrand. From 1930 to 1931, von Ulf got a Rochester Fellowship to do his post-doctoral studies abroad. He studied in England with Sir Henry Dale in London and with I. de Burgh Daly in Birmingham, and then proceeded to the continent, studying with Corneille Heymans in Ghent, Belgium and with Gustav Embden in Frankfurt, Germany. Von Euler liked to travel, so he also worked and learned biophysics with Archibald Vivian Hill, again in London in 1934, and neuromuscular transmission with G. L. Brown in 1938. From 1946 to 1947, he worked with Eduardo Braun-Menéndez in the Instituto de Biología y Medicina Experimental in Buenos Aires, which was founded by Bernardo Houssay. His unerring instinct to work with important scientific Leaders and fields was to be proved by the fact that Dale, Heymans, Hill and Houssay went to receive the Nobel prize in physiology or Medicine.