The present article deals with avoidance of the contract for non-conformity of goods and the requirement of fundamental breach in the United Nations Convention on Contracts for the International Sales of Goods (CISG). In order to avoid a contract for the lack of conformity a fundamental breach is required, hence the study firstly analyses the requirement of fundamental breach defined in article 25 CISG. Secondly, we try to find out how the buyer can avoid the contract under article 49(1)(A) CISG with referring to the numerous decisions of courts and arbitral panels. Finally, the analysis focuses on seller’s right to cure after the delivery date and interaction between right to cure and avoidance.