Competitive dialogue (CD) is a seldom-practised procurement procedure in Norway. The Norwegian Public Roads Administration (NPRA) plans to use it in complex and mega infrastructure project in the future. This study investigates how CD has contributed to the implementation of lean in the public sector by answering the following two research questions: What are the motives for using CD?; and How was the CD carried out (timeline, main activities etc.)? With a supporting literature study, four cases were studied by conducting a document study and semi-structured in-depth interviewees with eight key informants. Several motives why CD has been used in the target projects were identified. However, none the identified motives were to directly implement lean. Furthermore, eleven major activities of CD and two project implementation models that have used CD were identified in the case projects. The motives behind implementing CD are found to be comparable to the motives for implementing lean construction principles. In addition, the dialogue phase is found to be at the core of the process and could contribute to reducing significant waste. The findings provide a contribution of how CD can be used to implement lean in public procurement.