The invention relates to a sterilization system (1) for an aseptic containers production machine. The system (1) comprises: an airflow inlet section (2) for the entrance of an airflow a first filtering group (3), disposed downstream with respect to the airflow inlet section (2) and communicating with the latter for receiving the airflow a second filtering group (4), disposed downstream with respect to the first filtering group (3) for receiving the airflow exiting from the first filtering group (3). The system (1) further comprises: a connection zone (5), connecting the first filtering group (3) to the second filtering group (4) supplying means (6) for supplying a sterilization substance and an airflow exiting section (7), disposed downstream with respect to the second filtering group (4) and communicating with the latter for allowing the exit of the airflow containing the sterilization substance. In particular, the connection zone (5) defines an airflow passage conduit comprising: a first section (51) communicating with the first filtering group a second section (52) communicating with the second filtering group (4) and a third section (53) interposed between the first section (51) and the second section (52), and smaller than the first section (51) and the second section (52). Furthermore, in the system (1), the supplying means (6) are designed for supplying the sterilization substance at the third section (53) of the connection zone (5), optimizing the sterilization substance distribution in the airflow.
