Geophysical data combined with pressure-temperature-time data form the basis for a reconstruction of the kinematic evolution of the Scandinavian Caledonides collisional orogenic belt. The reconstruction suggests that the early stages of collision between Baltica and Laurentia involved intracontinental subduction of a minimum of 150 km of Baltic continental crust to a depth of at least 100 km. The subduction juxtaposed strong, Laurentian upper mantle rocks in the upper plate against weak, Baltic crustal rocks in the lower plate. Continued plate convergence, coupled with the buoyancy of the Baltic rocks, resulted in thrust imbrication of a substantial portion of the lower plate and extrusion of the crustal rocks from the subduction zone. Thrusting also resulted in incorporation of fragments of the Laurentian upper mantle into the Baltic crust. The reconstruction also suggests that direct interaction between the Laurentian and Baltic crustal rocks, and the time of greatest crustal thickness in the orogen, occurred after extrusion of the Baltic crust from the subduction zone. One implication of this suggestion is that the eclogite/coesite assemblage presently exposed at the surface in the hinterland of the Caledonides probably formed early in the collision sequence during subduction rather than during the time of greatest crustal thickness. The reconstruction also suggests that exposure of the high-pressure mineral assemblage was a two-phase process, involving extrusion from the subduction zone by thrusting during convergence and unroofing by a combination of extension on low-angle normal faults and erosion. The kinematic model derived for the Scandinavian Caledonides provides a possible scenario for the evolution of other collisional orogenic belts, containing veyr high-pressure mineral assemblages formed in situ in continental rocks and associated ultamafic rocks of mantle origin. ¿ American Geophysical Union 1996