The IURU organizes the Combined Universities Representative Rugby Team which competes annually. While the Irish Universities side had played games against other Irish representative sides since the 1930's the first game against International opposition (Scottish Universities)was played in 1954. In the past the Combined Universities played against full test teams, e.g. against the All Blacks in 1974 and beat the Springboks in 1965 in Thomond Park. Since the advent of professional rugby, test matches against full senior international sides have become a thing of the past, however the IURU has continued to arrange annual international fixtures against other National Universities sides from France, England, Wales and Scotland and against IRFU developmental sides.The most recent Combined University fixture was held in March 2014 against an Irish Exiles side in Ealing which the Combined Universities won by 53:06. The Combined Universities have toured overseas on 4 occasions, to New Zealand in 1978, to Japan & South Korea in 1987, to South Africa in 1994 and to Australia in 1997. The Combined Universities team players wear their respective clubs socks with the green international jersey.
The IURU also organizes four domestic tournaments across different grades on an annual basis;
The Dudley Cup is the senior inter university competition and is named after Lord Dudley, former Viceroy of Ireland who donated the trophy following a visit by King Edward VII to what became UCC in August 1903. The first Dudley Cup final was held in March 1904 with Queens University Belfast the inaugural winners. The Dudley Cup has been competed for on 62 occasions and to date University College Cork have taken the most titles with 20 successes . In recent years it has been competed for by the 4 clubs in the IURU with senior club (AIL) status. It has been recently organised on the following basis, with the two Division 2B sides AIL game doubling up as one semi-final and UCD and TCD's annual colours game doubling up as the other semi-final. The final of the Dudley Cup for season 2012-2013 was fought out between QUB and TCD with Queens coming out on top on a 16:13 score line. The 2013-2014 final will be played between UCD and UCC.
The Conroy Cup is the U-20s level inter-varsity rugby tournament. It was inaugurated in 1988 and is played over a weekend hosted in turn by one of the member universities. It is named in honour of father and son " Judge" Conroy & Paddy Conroy both past Presidents of UCD RFC. Unlike the Dudley Cup, both NUIG and NUIM take part in this competition. The Conroy Cup for season 2013-2014 was held for the first time in the National University of Ireland, Maynooth campus with 6 Universities competing, TCD pipped UCD in a closely fought final on a 13:8 scoreline.
The Maughan-Scally Cup is the junior inter-varsity rugby tournament. It was inaugurated in 2010 and is named after two stalwarts of UCD RFC and university rugby in Ireland. It is played over a weekend and hosted in turn by one of the member clubs. The 2013-2014 competition was held in Cork with 4 sides competing and NUIG RFC emerging victorious. The Maughan-Scally is considered to be the most social, enjoyable and "old school" of the inter-varsity weekends.
The Kay Bowen Trophy is the ladies inter-varsity rugby tournament. It was inaugurated in 2012 and is named after Kay Bowen past President of Dublin University Rugby Club. The competition is played over a weekend and is hosted in turn by one of the member clubs. It was held in 2013-2014 in the UCD grounds in Belfield with 4 sides competing. A strong NUIG side saw off 2012-2013 winners Trinity in the final.