He also performs regularly in a piano duo with his sister, Luba Zuk. Since 1982, the duo have made frequent tours, particularly in Europe, where they have played concerts in major centers.  More recently, they have become frequent visitors in Ukraine where they have appeared in major cities and at seven international music festivals.  Many works by Canadian composers have been premiered by the duo.  They have also commissioned a significant number of works, some under awards from the Canada Council and the Ontario Arts Council. Their recordings have been included in the RCI Anthology of Canadian Music, and recently the SNE (Societe nouvelle d'enregistrement) has released a CD of works by Canadian composers.

In Kyiv, Ukraine, Ireneus Zuk served as jury member of the Horowitz Competition for Young Pianists (1995, 2000, 2006) and of the "Farbotony" competition and also as Chair of the State Examination Commission (of the Ministry of Culture) at the Tchaikovsky Conservatory.   He has been a juror of the Eckhardt-Gramatte Competition for the Performance of Contemporary Music in Canada, of the Klasinc Competition in Slovenia, Les Rencontres des Jeunes in Belgium, the 1000 Islands International in the USA and annually since 1996 on the jury of the IBLA Grand Prize International Piano Competition in Italy.

The government of Ukraine honored Ireneus Zuk with the award of a medal and the title "Merited Artist of Ukraine."  The Ukrainian Canadian Congress awarded him the Shevchenko medal in recognition of his promotion of Canadian and Ukrainian-Canadian music.