The fifth triennial International Congress of the International Union of Crystallography was held in Cambridge, England, from August IS through 24, 1960. In addition to nearly 450 general papers classified under 19 different headings, there were 5 general lectures on different specialized topics, a panel discussion on the theory of metals, and two symposia. The first symposium had some 36 contributions concerning thermal motion in crystals and molecules; the second consisted of about 100 papers dealing with lattice defects and the mechanical properties of solids. Abstracts of all contributions, including the symposia, will appear soon as an issue ofActa Crystallographica; most of the abstracts indicate where detailed publication is planned. Eight of the Russian contributions appeared in an issue ofKristallografiya(Vol. 5, No. 4, 1960) which was distributed at the congress.