DISC, the International Symposium on DIStributed Computing, is an annual forum for research presentations on all facets of distributed computing. This volume includes 23 contributed papers and an invited lecture, all presented at DISC ’99, held on September 27-29, 1999 in Bratislava, Slovak Republic. In addition to regular submissions, the call for papers for DISC ’99 also – licited Brief Announcements (BAs). We received 60 regular submissions and 15 brief announcement submissions. These were read and evaluated by the p- gramcommittee, with the additional help of external reviewerswhen needed. At the program committee meeting on June 10-11 at Dartmouth College, Hanover, USA, 23 regular submissions and 4 BAs were selected for presentation at DISC ’99. The extended abstracts of these 23 regular papers appear in this volume, while the four BAs appear as a special publication of Comenius Univ- sity, Bratislava- the hostof DISC ’99.It is expected that the regularpapers will be submitted later, in more polished form, to fully refereed scienti?c journals. Of the 23 regular papers selected for the conference, 12 quali?ed for the Best Student Paper award. The program committee awarded this honor to the paper entitled "Revisiting the Weakest Failure Detector for Uniform Reliable Broadcast" by Marcos Aguilera, Sam Toueg, and Borislav Deianov. Marcos and Borislav, who are both students, share this award.