Depression in the elderly is common and exhibits a distinctive phenomenology, due to neurobiological, physiological, psychological and social changes related to ageing. Most elderly with depression are managed in primary health care. Although the number of scientific publications related to geriatric psychiatry has increased, there are still important gaps. Implementation of evidence-based guidelines for managing depression in primary care has had limited success, but has led to improvements compared to standard care. It is logical that the determinants (barriers and enablers) of implementing depression guidelines can be identified and can guide the selection of more effective implementation strategies that are tailored to address those determinants. We are testing that logic as part of a multinational implementation research project called 'Tailored Implementation for Chronic Diseases' (TICD). Our focus in Norway is on the management of depression in the elderly in primary care. We will identify the determinants of implementing evidence-based recommendations using various methods and comparing those methods. We will then use different methods to match the implementation interventions to the identified determinants and compare those methods. Finally, we will evaluate the resulting tailored implementation strategy in a randomized trial.