In 1935, he completed a research internship in France at the University of Paris and in the Netherlands, where he was an assistant for Hans Kramers and later studied under Adriaan Fokker and Léon Rosenfeld.
[5] Opechowski moved to Leiden University in 1939 and remained working there until 1945.
[6][1] Opechowski emigrated to Vancouver, Canada in September 1948 and became a professor of physics at the University of British Columbia[7] and remained there for the rest of his career.
[citation needed] Opechowski served as the Lorentz chair and delivered the invited lecture at Leiden University from 1964 to 1965.
[1] He received the Marian Smoluchowski Medal from the Polish Physical Society in 1982.