He was among the top dozen chess players in the world from 1910 to 1930 and in 1950, was among the inaugural recipients of the title International Grandmaster from FIDE.

The study of electrical engineering at the Technical faculty did not begin until 1904, so Vidmar had to take special examinations in the field basics.

[1] He was a professor at the University of Ljubljana, a member of the Slovenian Academy of Arts and Sciences, and the founder of the Faculty of Electrical Engineering.

His successes include high places at some of the top chess tournaments of his time, e.g. sixth at Carlsbad 1907, third at Prague 1908, first at Gothenburg 1909 (the 7th Nordic Chess Championship), second at San Sebastián 1911 with Akiba Rubinstein behind José Raúl Capablanca, first at Budapest 1912, second at Mannheim 1914, first at Vienna and Berlin in 1918, second at Košice 1928, third at London 1922, shared first with Alexander Alekhine at Hastings 1925/26, third at Semmering 1926, fourth at New York 1927, fourth at London 1927, shared fifth at Carlsbad 1929, tied for 4–7th at Bled 1931, tied for 3–6th at Stuttgart 1939, second behind Max Euwe at Budapest 1940, first at Basel 1952.

The Slovene Chess Federation organizes an international grandmaster tournament named the Milan Vidmar memorial.