One form of business activity that is prohibited in business competition law is monopolistic practices, which is a form of market control. One of the cases of monopolistic practices is related to lobster seed export services involving the freight forwarder company PT ACK. This research aims to study the role of the government in preventing monopolistic practices as well as the responsibility of freight forwarder companies that commit such monopolistic practices. This research uses a normative juridical research method. The results of this study show that the role of the government, namely KPPU, has not been maximised in preventing the monopoly of lobster seed exports. KPPU has conducted a study with several parties related to lobster seed exports and found no regulations that designate only one company that can export. However, the fact is that in the field, only PT ACK can export. The company that committed monopolistic practices has been found guilty of violating Article 17 of Law Number 5 of 1999 in KPPU Decision Number 04/KPPU-I/2021 and bears the responsibility of terminating its business activities and seizing assets for the state.