By 1982, the central analysis team of this on-going multinational survey had received a total of 8,723 cases for analysis and had accepted 8,480. In all some 23 centres in 15 countries, involving over 200 doctors had participated in this survey. A common protocol was used for data collection; around 98% of all possible data was recorded (using pre-circulated definitions) and analysed via a computer-aided system in Leeds, England. As before, the most common surgical diagnosis was acute appendicitis (2336 of 8,480 cases, 27.5%) followed by acute cholecystitis (800 cases, 9.4%). The construction of a worldwide database of information about 6.097 patients is described--as is its use both in diagnosis and in teaching. Particular attention is given to the construction of a computer program which allows medical students to compare their impression of acute abdominal pain with 'reality' as evidenced in these 6,097 patients. As regards additional cases, particular stress has been laid on acquisition of material from countries outside Europe and North America. Series from Mexico (893 patients) and Thailand (311 patients) are discussed in detail, and the implications for future work are reviewed.