Ph 61 401991111 (8400 words)Indexing words: dynamism, dynamic, planning, emergent, iterative project management Abstract Rapidly changing environments are a newly recognized and increasing challenge in the field of project management. Traditional prescriptive approaches, orientated around process control, are considered sub-optimal in meeting this challenge. In this article, the authors present an exploratory theorybuilding study aiming to identify the project management approaches used by experienced practitioners to respond to rapidly changing environments. The results of thirty-seven semi-structured interviews with thirty-one participants across ten industries (i.e. construction, aerospace, international community development, pharmaceutical, defense, film production, startups, venture capital, research, and information technology) were analyzed according to the planning styles used. Results are discussed in the light of previous research and a model for better management in rapidly changing environments proposed.Pre-publish draft.