Abstrack The tectonic history of Northern Central America can be traced to mid-Paleozoic time, when a marginal geosyncline was present soulh of the foreland platform which occupied approximately the present Yucatân Peninsula. Before Pennsylvanian time, the geosynclinal sediments were intensely deformed, metamorphosed, and intruded by granitic rocks; during Pennsylvanian-Permian time, they were covered by an unconformable clastic wedge of sediments. Late Permian to Early Triassic uplift and folding resulted in the emergence of a land area, more extensive than present Northern Central America, which probably extended eastward across the area now occupied by the Nicaragua Rise. Large longitudinal faults along the crest of the uplift marked the beginning of such features as the Bartlett Trough and the Cayman Ridge. A new depositional episode started in Late Jurassic time and continued through most of Cretaceous time, resulting in the formation of the Mexican geosyncline, which covered a large part of Northern Central America. Deformation of its marginal area during middle Cretaceous time was accompanied by granitic intrusions in two arcuate belts; the one in northern Nicaragua probably extended along the Nicaragua Rise. The geosynclinal sediments were folded intensely during Late Cretaceous to early Tertiary time, and there was contemporaneous deposition of a clastic wedge. Evidence in northern Honduras suggests Late Cretaceous volcanic activity, and it is possible that more intensive volcanic activity took place on the Nicaragua Rise, together with activity in other parts of the northern Caribbean region. The orogenic movements were followed by emergence and block faulting during Oligocene time, and by widespread vblcanism (basalt to rhyolite) during late Tertiary time. Of special interest in the tectonic history of Northern Central America is a wide belt of serpentinite that essentially parallels major faults along the Bartlett Trough trend. The serpen- tini te may represent mantle material injected early in the tectonic history of the area and remobilized several times. It was exposed on the surface for the first time during the Late Cretaceous deformational episodes. The relations of Northern Central America, the Yucatan basin, and Cuba are one of the major unsolved problems in the tectonic history of this area.