The nature and development of the recently released International English Language Testing System (IELTS) instrument are described. The test is the result of a joint Australian-British project to develop a new test for use with foreign students planning to study in English-speaking countries. It is expected that the modular instrument will become the principal test taken by overseas students intending to study or train in Australia or Great Britain, and comprehensive test administration procedures are being established in most parts of the world. It assesses both general proficiency and English for academic and other special purposes in one of four broad discipline areas (general training, arts and social sciences, physical sciences and technology, and life and medical sciences). An introductory section offers background information on the test construction process, and subsequent sections describe in greater detail the test format, subtests and specifications, efforts to make the test international in nature and to limit cultural bias, and issues in test management and administration. A brief bibliography is included. (Author/MSE)