Corruption is embedded in health systems. Throughout my life—as a researcher, public health worker, and a Minister of Health—I have been able to see entrenched dishonesty and fraud. But despite being one of the most important barriers to implementing universal health coverage around the world, corruption is rarely openly discussed. In this Lecture, I outline the magnitude of the problem of corruption, how it started, and what is happening now. I also outline people's fears around the topic, what is needed to address corruption, and the responsibilities of the academic and research communities in all countries, irrespective of their level of economic development. Policy makers, researchers, and funders need to think about corruption as an important area of research in the same way we think about diseases. If we are really aiming to achieve the Sustainable Development Goals and ensure healthy lives for all, corruption in global health must no longer be an open secret.