Chronic diseases are of growing importance. While non-communicable diseases currently seem to be capturing the agenda, both chronic infectious and non-infectious diseases, pose major challenges to health systems in high and low-incomes countries in stable and emergency situations. The long-term nature of many chronic conditions warrants a comprehensive and sustainable health systems response that brings together a trained workforce with appropriate skills, affordable and reliable supplies of medicines and technologies, and empowerment of patients and communities. These new realties reflect the interplay of various factors such as changing lifestyles, economic development and urbanization. The need for a multi-sectorial response has never been greater. These challenges present new opportunities for science and technology to contribute to the improvement of access to health.