The origins of the Institute date back to 1928, when the Irish Association of Advertising Agencies was founded. The Institute replaced it in 1964 and for 30 years has represented the interests of advertising agencies in the Ireland. IAPI is comprised of 36 member companies, accounting for over 95% of advertising agency expenditure in the country.

A non-profit making company, the Institute has a secretariat of 13 and is governed by a Board of 12 Directors, elected annually. Its activities, co-ordinated by the IAPI committees are wide-ranging and include negotiations with the media, trades unions and government, as well as lobbying at the European Commission and Parliament. The Institute is a long-serving member of the European Association of Advertising Agencies.

As the central authority for media research, the Institute provides the secretariats for the Joint National Readership Research (JNRR) and the Joint National Listenership Research (JNLR) surveys and is a partner with RTE in the Nielsen television measurement service. Close liaison is maintained with the Association of Advertisers in Ireland (WFA) including the joint publication of Guidelines. As a founder member of the Advertising Standards Authority in Ireland, the Institute is represented on both its Board and its Complaints Committee. Through the Joint Advertising Education Committee, it supervises the post-graduate advertising course at DIT Aungier Street.