Project theory is not only an immature field of research, it is insubstantial when it comes to understanding what is really going on in projects. This paper contributes to making project research matter to the academic as well as the practitioner through the theoretical development of a project-as-practice approach, aligned with an ongoing debate in social science research. We outline the framework of project-as-practice and argue that there are two major challenges to the researcher: the relevance challenge and the pattern challenge. We suggest how these challenges can be met and give some examples of earlier studies that have done so. The practice approach is not a substitute to present theorizing but rather a complement that brings substance. Finally, underlying notions of the practice approach are outlined in order to have a fruitful future development of a project-as-practice approach that makes project theory matter!