Smej was born in Bogojina, Slovenia and was ordained a priest on 8 December 1944. Smej was appointed auxiliary bishop of the Archdiocese of Maribor, as well as titular bishop of Tzernicus, on 15 April 1983 and ordained bishop on 23 May 1983.
Smej held the position of auxiliary bishop of the Maribor diocese until his retirement on 18 June 2009.