The adoption of the Convention on Contracts for the International Sale of Goods (CISG), the UNIDROIT Principles of International Commercial Contracts, and the Principles of European Contract (PECL) has marked a new step in development of international commercial law. Resulting from considerable efforts to unify and harmonise international commercial and, in case of the PECL, European law, these Instruments have become important and truly international sources of contract and commercial law. The thesis seeks to examine the remedy of damages under these Instruments. Damages are a key remedy because, amongst other reasons, it is likely to be exercised more often than any other remedy and can be used exclusively or in conjunction with other remedies. The examination is confined to international sales transactions. The work examines some of the central parts of the law of damages such as the definition and purposes of the award of damages; basis for the right to claim damages; principles underlying the award of damages; the idea of limiting damages; classification of losses; categories of loss; causation; foreseeability; mitigation; standards of proving loss and determining the amount of damages. The work draws heavily on cases decided in various jurisdictions and arbitration tribunals and uses the method of comparative analysis which helped identify the problems that had to be addressed and provided a wider range of possible solutions. However, every solution put forward by this work is based on the mandate of the Instruments to respect their autonomous and international character and the need to promote uniformity in their application as well as on the author's views as to what are the policies, considerations, and values that underlie the Instruments. The work is original in terms of its scope and the extent to which the issues relating to damages under these Instruments are examined.