One of the tasks of public libraries is to provide access to a variety of materials, which most libraries gather in one place and call it a library collection. Public libraries today have an increasing number of different collections that should be properly presented to users. Today, marketing and the Internet have a big role in that, so a large number of public libraries have recognized the importance of networking as a marketing tool to help promote their collections. Scientific literature does not offer much research into the promotion of collections on web pages, especially on the promotion of collections using Web 2.0 tools. Because of that, purpose of this paper is to highlight the importance of promoting library collections on library web pages and to highlight all possibilities that Web 2.0 tools can provide. The purpose of this paper is to explore how many libraries have used their web pages to promote library collections, and examine to what extent Croatian public libraries promote their collections on their web pages and, also, are they using features of Web 2.0 tools. Analysis of the twenty web pages of public libraries and of their publishing with Web 2.0 tools, provided insights whether libraries promote their collections on web pages and with Web 2.0 tools. The research has indicated diversity of library collection promotion and the ability to develop library collection on web pages using Web 2.0 tools