This study aims to analyze the provisions of the Material Adverse Change (MAC) clause as a legal basis for exiting an acquisition agreement and to examine the legal consequences arising from the application of the clause. This study uses normative legal research with a conceptual approach, a statutory approach, and a comparative approach. The results of the study indicate that the basis for its philosophical application refers to the principles of justice and balance, while the basis for its written legal application refers to international agreements such as the Unidroit Principles of International Commercial Contracts (UPICC) and the International Chamber of Commerce (ICC). In Indonesia, the validity of the MAC clause in Indonesia comes from the principle of freedom of contract as stated in Article 1338 paragraph (1) of the Civil Code and the principle of good faith as regulated in Article 1338 paragraph (3). In addition, the MAC clause can be linked to the principle of risk allocation in business contract law. Cancellation of an acquisition transaction based on the MAC clause has legal consequences such as legal status with third parties, reversion to the original state, and administrative company establishment. Therefore, it is necessary to formulate a more specific and proportional MAC clause in order to guarantee legal certainty, justice and protection for the parties in the acquisition transaction.