Respiratory diphtheria is an acute respiratory tract infection. The high mortality rates (5-10%) are related to airway obstruction and local and systemic effects of the diphtheria toxin. Vaccination against diphtheria has been available through the Dutch national vaccination programme since the 1950s. The disease has now become rare as a result of herd immunity by these vaccinations. As a consequence, the disease has largely been forgotten, which can result in it not being recognised and treated in time. In addition, diphtheria antitoxin is not always available. In this article, we are drawing attention to the need for immunisation. We also look back at how diphtheria prevention started in the Netherlands.