Whooping cough (pertussis) is a contagious disease caused by Bordetella pertussis that can be prevented by vaccination. The disease is particularly severe in infants who are less than 3 months old, who are not protected against the disease and are often contaminated by their parents. Atypical presentations are frequent and neonatal pertussis is rare. We report a case of malignant whooping cough in a newborn infant probably contaminated by her mother. Diagnosis was suspected clinically because of persistent coughing fits and was confirmed by serology. Treatment was successful. We discuss the diagnostic, therapeutic, and preventive issues of whooping cough in developing countries. In Africa, where complementary investigations such as PCR are seldom accessible, a careful clinical study and the analysis of the absolute rate of lymphocytes could be an alternative for the diagnosis of whooping cough. Vaccination of teenagers and adults is also problematic in poor countries. High-performance new vaccine candidates may contribute to a better control of whooping cough.