A rapidly spreading invasive mosquito is raising fresh concerns about malaria across Africa as health experts warn it could reverse years of progress in controlling the disease. Unlike traditional malaria-carrying mosquitoes, ‘Anopheles stephensi’ thrives in densely populated urban environments, breeding in water containers around homes and buildings rather than rural wetlands. Scientists are particularly concerned because the species has developed resistance to many of the insecticides currently used in malaria control programmes, making it much harder to eliminate. As African cities continue to grow, millions more people could become vulnerable to malaria outbreaks in places where the disease has previously been less common. Researchers are urgently developing new approaches, including biological control methods, innovative technologies, and next-generation insecticides, while emphasising that international cooperation will be essential to contain the threat. The emergence of this resilient mosquito highlights the ongoing challenge of protecting public health in rapidly changing urban environments.