Capacity building is widely recognised as an important component of most research-for-development activities. However despite the fact that around $15 billion is spent annually on capacity building activities, there has been limited assessment of the economic returns to that investment. In recent years, the Impact Assessment Program of the Australian Centre for International Agricultural Research has turned its attention to quantifying the benefits from capacity-building. This paper sets out a framework for assessing of the impact of capacity building and presents four case studies. It does not purport to be a definitive paper by any means. Rather, it is an account of just one organisations experience. It is hoped that as work on this important area continues, and as new capacity building-to-impact pathways emerge, the analytical framework presented here will continue to be updated.