Background: There is a poor understanding of to how to recruit and involve primary care dentists in clinical trials. Aim: To use a qualitative paradigm to explore the views of primary care dentists towards participating in clinical trials and develop an understanding of the factors that facilitate and prevent their involvement. Design, setting, subjects and methods: An iterative approach was undertaken using a focus group (n = 6) followed by phased semi-structured interviews (n = 18). Data were analysed using thematic analysis and constant comparative analysis. Findings: The semi-structured interviews generated nine codes which were organised into three themes: technical issues for trials in primary dental care, practical issues for research in primary dental care and primary care dentists as research consumers. Overall, primary care dentists had a poor understanding of research methodology and clinical research. Barriers to participation included loss of clinical freedom and control, practice disruption, patient welfare, staff workload, financial loss and time. Conclusions: Barriers to primary dental care research need to be overcome through appropriate protocols, funding, training and support. Joint working of primary dental care teams and academic researchers is essential, along with a constructive and open dialogue, if clinical trials are to be successfully undertaken in a practice environment. © 2011 Macmillan Publishers Limited. All rights reserved.