This volume contains the proceedings of the Third International Workshop on Hybrid Systems: Computation and Control (HSCC 2000), which was held on March 23-25, 2000, in Pittsburgh, Pennsylvania. The proceedings of the rst two workshops in this series were published by Springer-Verlag, in the Lecture Notes in Computer Science series, as volumes 1386 and 1569. The focus of the Hybrid Systems workshop series is on modeling, control, synthesis, design, and veri cation of hybrid systems. A hybrid system is a th- reticalmodelforacomputercontrolledengineeringsystem, withadynamicsthat evolvesbothinadiscretestatesetandinafamilyofcontinuousstatespaces.- brid systems researchis motivated by, for example, controlof electro-mechanical systems(robots), air tra ccontrol, controlofautomatedfreeways, andchemical process control. The research area of hybrid systems overlaps both with c- puter science and with control theory. The workshop series is intended to foster the interaction between researchers from these elds in addressing problems in this new domain. The scientic program of the workshop consisted of four invited talks and 32 contributed talks. The following researcherspresented invited talks: K. Butts (Ford Research, USA), N. Leveson (MIT, USA), A. Sangiovanni-Vincentelli (U. California, Berkeley, USA), and B. Williams (MIT, USA). The contributed talks were based on the papers in these proceedings. The program committee, chaired by the editors, selected the 32 contributed papers out of 71 submitted papers. The editors are grateful to the members of theprogramcommitteefortheir generoushelpinthereviewingandtheselection process.