Background: A tailored approach to implementation can facilitate the routine use of best evidence, and so improve the quality of care delivered. Tailored implementation involves investigating the context and barriers to change before selecting appropriate interventions. However, there is little evidence on the methods of tailoring. This study investigated the tailoring undertaken by two implementation groups as part of a study to improve adherence to NICE guidelines on adult obesity in primary care. Methods: Data were collected from interviews with healthcare professionals and patients on barriers and enablers to implementing NICE guidelines on adult obesity along with practice performance data on body mass index (BMI) recording and use of interventions for obesity. Findings were presented to medical practitioners, university and NHS staff (n = 12) who formed two implementation groups to independently identify the most important barriers and enablers, and to suggest interventions to facilitate the implementation of the NICE guidelines. Each group had a facilitator and were observed by researchers whose notes were used to understand the group processes and assess the usefulness of this method. Results: Within the time available both implementation groups reached consensus on the most important barriers and enablers and, led by those who had personal experience of managing patients with weight problems, made practical proposals for interventions to improve the implementation of the NICE guidelines. The role of the facilitator was crucial in ensuring barriers, enablers and interventions were all discussed and agreed upon in the time available. Conclusions: The facilitated implementation groups method succeeded in identifying appropriate and similar barriers, enablers and implementation interventions, which suggests some justification for this approach to tailoring. However, further research into methods of tailoring is required. Improvements to the implementation group approach may be realised by careful selection of group members and provision of sufficient preparation time prior to group discussions.