The phenomenon of the hidden economy is one of the most important causes of the economic crisis that Chad has witnessed since 2016 CE, and it led to the adoption of a set of austerity measures (16 measures), which necessitated the necessity of examining this phenomenon, knowing its causes and finding appropriate solutions to it.      The importance of the study lies in the fact that it focuses mainly on the phenomenon of the hidden economy in Chad, due to its negative effects other than the economic effects.       The study relied on the descriptive approach, the analytical method, and the inductive approach, and to achieve the aim of the study, it was divided after an introduction into three investigations and a conclusion that includes findings and recommendations.