Background and context. Currently, in New Zealand general practice, the introduction of new initiatives is such that interventions may be introduced without an evidence base. A critical role is to respond to the challenges of chronic illness with self-management a key component. The ‘Flinders Model’ of self-management collaborative care planning developed in Australia has not been evaluated in New Zealand. A study was designed to assess the usefulness of this ‘Model’ when utilised by nurses in New Zealand general practice. This paper describes the issues and lessons learnt from this study designed to contribute to the evidence base for primary care. Assessment of problems. Analysis of interviews with the nurses and the research team allowed documentation of difficulties. These included recruitment of practices and of patients, retention of patients and practice support for the introduction of the ‘new’ intervention. Results of assessment. A lack of organisational capacity for introduction of the ‘new’ initiative alongside practice difficulties in understanding their patient population and inadequate disease coding contributed to problems. Undertaking a research study designed to contribute to the evidence base for an initiative not established in general practice resulted in study difficulties. Lessons learnt. The need for phased approaches to evaluation of complex interventions in primary care is imperative with exploratory qualitative work first undertaken to understand barriers to implementation. Collaborative partnerships between researchers and general practice staff are essential if the evidence base for primary care is to develop and for ‘new’ interventions to lead to improved health outcomes.