Existence of an adequate project champion role has been identified as a critical success factor in ERP implementation projects. However, the figure of the project champion is not yet quite well understood. Some authors relate it with the project sponsor figure while others relate it with the project manager figure. This paper tries to clarify these concepts. Our research framework has been based upon an extensive ERP literature review and a web survey. The findings of this survey show that the adequate project champion role is that of the project sponsor; respondents also think that both project manager and project sponsor are critical to the success of an ERP implementation project and not merely the project champion figure. We also show the interdependence between project sponsor role, project manager role and ERP project success, for which we present an interdependence model.