In the wake of healthcare disasters, such as the appalling failures of care uncovered in Mid Staffordshire, inquiries and investigations often point to a litany of early warnings and weak signals that were missed, misunderstood or discounted by the professionals and organisations charged with monitoring the safety and quality of care. Some of the most urgent challenges facing those responsible for improving and regulating patient safety are therefore how to identify, interpret, integrate and act on the early warnings and weak signals of emerging risks—before those risks contribute to a disastrous failure of care. These challenges are fundamentally organisational and cultural: they relate to what information is routinely noticed, communicated and attended to within and between healthcare organisations—and, most critically, what is assumed and ignored. Analysing these organisational and cultural challenges suggests three practical ways that healthcare organisations and their regulators can improve safety and address emerging risks. First, engage in practices that actively produce and amplify fleeting signs of ignorance. Second, work to continually define and update a set of specific fears of failure. And third, routinely uncover and publicly circulate knowledge on the sources of systemic risks to patient safety and the improvements required to address them.