Cameron J Phillips,1,2 Andrea P Marshall,3,4 Nadia J Chaves,5 Stacey K Jankelowitz,6,7 Ivan B Lin,8 Clement T Loy,9,10 Gwyneth Rees,11 Leanne Sakzewski,12 Susie Thomas,13,14 The-Phung To,15 Shelley A Wilkinson,16,17 Susan Michie18 1Division of Pharmacy, Flinders Medical Centre, Bedford Park, SA, Australia; 2School of Medicine, Flinders University, Adelaide, SA, Australia; 3Centre for Health Practice Innovation, Griffith Health Institute, Griffith University, Southport, QLD, Australia; 4Gold Coast University Hospital, Southport, QLD, Australia; 5Victorian Infectious Diseases Service, Royal Melbourne Hospital, Parkville, VIC, Australia; 6Central Clinical School, Sydney Medical School, University of Sydney, 7Institute of Neurosciences, Royal Prince Alfred Hospital, Sydney, NSW, Australia; 8Western Australian Centre for Rural Health, University of Western Australia, Geraldton, WA, Australia; 9School of Public Health, Sydney Medical School, University of Sydney, Sydney, NSW, Australia; 10Huntington Diseases Centre, Westmead Hospital, Westmead, NSW, Australia; 11Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia; 12Queensland Cerebral Palsy and Rehabilitation Research Centre, University of Queensland, Brisbane, QLD, Australia; 13Physiotherapy Department, Flinders Medical Centre, Bedford Park, SA, Australia; 14International Centre for Allied Health Evidence (iCAHE), School of Health Sciences, University of South Australia, Adelaide, SA, Australia; 15Pharmacy Department, Austin Health, Heidelberg, VIC, Australia; 16Mater Research Institute, The University of Queensland, South Brisbane, QLD, Australia; 17Department of Nutrition and Dietetics, Mater Health Services, South Brisbane, QLD, Australia; 18University College London Centre for Behaviour Change, Department of Clinical, Educational and Health Psychology, University College, London, UK Background: The Theoretical Domains Framework (TDF) is an integrative framework developed from a synthesis of psychological theories as a vehicle to help apply theoretical approaches to interventions aimed at behavior change. Purpose: This study explores experiences of TDF use by professionals from multiple disciplines across diverse clinical settings. Methods: Mixed methods were used to examine experiences, attitudes, and perspectives of health professionals in using the TDF in health care implementation projects. Individual interviews were conducted with ten health care professionals from six disciplines who used the TDF in implementation projects. Deductive content and thematic analysis were used. Results: Three main themes and associated subthemes were identified including: 1) reasons for use of the TDF (increased confidence, broader perspective, and theoretical underpinnings); 2) challenges using the TDF (time and resources, operationalization of the TDF) and; 3) future use of the TDF. Conclusion: The TDF provided a useful, flexible framework for a diverse group of health professionals working across different clinical settings for the assessment of barriers and targeting resources to influence behavior change for implementation projects. The development of practical tools and training or support is likely to aid the utility of TDF. Keywords: barriers and enablers, behavioral change, evidence-based practice, implementation, health care, Theoretical Domains Framework