Wall paintings are physically indivisible from the built heritage, which makes their conservation difficult. Conservation measures focus on stabilising paintings and slowing deterioration, while preserving significance and authenticity. Achieving these aims is complicated. The altered states in which paintings usually survive – due to events, exposure, neglect, misguided restorations, and other causes – do not always require stabilisation efforts, but their authenticity and significance may be severely undermined. At the same time, interventions to re-establish these values may expose paintings to physical risk. Balancing these dilemmas in practice requires constant evaluation of risks, objectives and outcomes. Conservation cannot be concerned with the attainment of conspicuous visual results while deterioration issues remain unaddressed. Neither can problems that impair the historic integrity and meaning of wall paintings be ignored. For over 30 years, the Courtauld Institute of Art, London, UK, has played a central role in educating conservators to meet the challenges of the discipline, through a well-established curriculum and a wide range of international projects in the field. From this perspective, this paper examines current challenges in wall painting conservation.