Introduction: Among the lessons learned from the 2009 influenza pandemic was the lack of a robust, standardized method that would allow a timely assessment of the severity of pandemic influenza. To remedy this deficiency, WHO has set up an evaluation tool based on the following indicators: 1) transmissibility, 2) seriousness of disease, and 3) impact of the influenza pandemic. By using this pandemic influenza severity assessment (PISA) tool, this study aimed to evaluate the severity of DRC influenza seasons between 2015 and 2019 to better prepare the country against the possible occurrence of an influenza pandemic. Methods: We performed a secondary data analysis from the DRC Influenza routine surveillance. We only explored the transmissibility among PISA indicators. Results: The results of our study showed that the DRC influenza seasons had two waves. The first went from the 40th week to the 10th week, with a peak at the 50th week, and the second wave ran from the 15th week to the 40th, with a peak at the 19th week. There was an inter-wave period between the 10th and 15th weeks. Of all the studied seasons, 42.8% were characterized by low intensity, 33.3% by moderate intensity, 19.0% by high intensity, and 4.8% by extraordinary intensity. Conclusion: The use of the PISA transmissibility indicator has contributed to better understanding influenza seasons in the Democratic Republic of Congo.