Purpose: This paper aims to understand how members of an organization with different backgrounds form an inter-professional knowing (IPK) from a collective authorship practice (CAP). Design/methodology/approach: This is a qualitative research drawn on an ethnomethodological approach on the committee responsible for the public policies of the waterfront for the city of João Pessoa, Brazil. The researchers spent one year observing the committee's meetings. Findings: The main result points out that IPK is a singular practice that emerges from the organization members' different backgrounds in a collective authorship process. Practical implications: It may be possible to adopt the notion of CAP as a methodology to address complex organizational problems. Originality/value: This paper presents the notion of IPK from a CAP based on an ethnomethodological approach.