The recent outbreak of diphtheria in Nigeria, despite mass vaccination coverage with the diphtheria-tetanus-pertussis vaccine in the country, has posed a public health concern for all Nigerians and the world at large. Recently, sporadic cases of diphtheria in Nigeria have been reported in more than 6 states in the country. Suspected and confirmed individuals with diphtheria in these states have developed severe complications, including the loss of lives as a result of the disease. This has caused panic for the majority of Nigerians and the international communities, as they feared that another epidemic of diphtheria could be on its way. Different factors, such as reduced awareness and campaigns on diphtheria, low socioeconomic status, inadequate income, inaccessibility to vaccination, war and displacement, and ineffective monitoring of the immunization schedule, as well as the emergence of coronavirus disease 2019 pandemic, could explain the recent sporadic outbreaks of diphtheria in Nigeria. This is a wide gap in knowledge about diphtheria in Nigeria that needs to be filled appropriately. As such, we recommend swift public health actions to be taken by the Nigerian government for quick health interventions for diphtheria to mitigate the current outbreak and future spread of the infection in Nigeria.