PurposeThe purpose of this paper is to describe the development of a co‐operative that facilitates interlending and document supply between health libraries in the Republic of Ireland.Design/methodology/approachThe development and expansion of the service are described from its origin in 1991.FindingsThe paper finds that the co‐operative has been a great success. Many documents could be supplied within the country, at a faster response rate and at a lower cost than by other methods. The number of journals in the scheme has increased from 1,009 to 7,283. Total number of article requests within the co‐operative has risen to 19,293.Originality/valueThis is the only article to give an up‐to‐date overview of an important national resource‐sharing health co‐operative in Ireland.