Competitive dialogue (CD) is a relatively new procurement procedure introduced in 2004 by the European Parliament for particularly complex contracts. The Norwegian Public Roads Administration (NPRA) has limited experience with the procedure, but they are planning to use it in several future projects. Limited research was found concerning the practical issues of CD. This paper explores the experiences of Norwegian practitioners to identify such issues and suggests measures for the success of future projects using the procedure. In addition to a literature study, a document study and twenty-two semi-structured in-depth interviews with key informants from six cases selected from the Norwegian public infrastructure projects were carried out. Both the client and the suppliers value the potential of CD. However, several challenges were identified, such as lack of practical experience with CD, ethical challenges, determining the MEAT (Most Economically Advantageous Tender) criteria, evaluation based on the MEAT criteria, and varying market interest. This paper contributes to construction engineering and management practice to increase the understanding of CD by suggesting what kinds of measures ought to be taken for the success of future projects using the procedure. Keywords-Competitive dialogue; procurement procedure; public projects; innovation; early contractor involvement. Competitive dialogue (CD) is a relatively new procurement procedure introduced in 2004 by the European Parliament for particularly complex contracts (European Commission, 2006). It a procedure that can be used to engage suppliers in the early phase of a project to support innovation (Edler and Georghiou, 2007; Korthals Altes and Taşan-Kok, 2010). In Finland, for instance, public traffic infrastructure owners have developed an alliancing project delivery method based on CD in order to implement ECI (Lahdenperä, 2009). In the Netherlands, CD and BVP have been used as approaches to implement ECI in the public sector (Van Leeuwen, 2011; Lenferink et al., 2012). Van Leeuwen (2011) explains how it is possible to combine CD with BVP to establish a procurement procedure that prioritizes qualification over price. In sum, CD has been found to enable the market to suggest innovative solutions (Kautsch et al., 2015) through the early involvement of suppliers, and to establishing an innovative public client-supplier relationship (Essig and Batran, 2005). The Norwegian Public Roads Administration (NPRA) is currently planning a mega project, the E39 Coastal Highway Route along the west coast of Norway. The project cost is estimated to be approximately 40 billion U.S. dollars. One of the main ambitions of the project is to make the E39 ferry free by replacing the eight ferry services crossing the major fjords with bridges and submerged tunnels. The fjords are up to 1,300 meters deep and 7,500 meters wide. As a consequence of the technical challenges involved, the NPRA needs to bring suppliers' knowledge and experience into the project to boost innovation. The NP...