Urolithiasis is a common disorder which is recognised in most parts of the world and occurs in both man and animals. The multifactorial nature of the problem requires an interdisciplinary approach which has always been a feature of this series of International Symposia which started in Leeds in 1968 and has progressed at four-yearly intervals through Madrid, Davos and Williamsburg. The latest Meeting, at Garmisch-Partenkirchen in April 1984, involved 302 participants from all five continents. The major emphasis of the Meeting was to blend the basic and clinical research on urolithiasis. Comprehensive reviews of the major areas of current research were presented by invited speakers, all internationally recognized experts in their fields. From more than 250 submitted abstracts, 18 were selected for oral presentation and the remainder presented at three afternoon poster sessions which provided an opportunity for informal and more lengthy discussions of the work on display. The Meeting also included three ad hoc Evening Discussions on how to approach various unsolved questions in the clinical and laboratory evaluation of stone patients and four Round Table Discussions involving specialists in the field who debated the theoretical aspects of stone formation in the urinary tract, the measurement of inhibitory activity of urine, the treatment of idiopathic stones with drugs, and the nature and treatment of stones arising from urinary tract infection.