New data are given on the Swedish Upper Jurassic and Lower Cretaceous sedimentary sequences, including unpublished subsurface documentation from the hydrocarbon prospecting, released for the IGCP Project Tornquist, as well as results from current mapping operations. A brief review is given on the Swedish Upper Jurassic and Lower Cretaceous sedimentary deposits, which are restricted to the southwestern margin of the East European Platform. Their distribution, depositional environments, lithology and stratigraphical representation are discussed. In terms of chronostratigraphy, foraminifers and ostracodes establish the presence of the Oxfordian, Kimmeridgian, and Portlandian Stages of the Upper Jurassic, and the Valanginian, Hauterivian, Barremian, Aptian, and Albian Stages in the marine Lower Cretaceous. A stratigraphy of Jurassic-Cretaceous transitional beds, which probably include Portlandian, Berriasian, and Valanginian non-marine strata, has yet to be established; consequently, the Jurassic-Cretaceous boundary in Sweden is still undefined. Swedish Upper Jurassic lithostratigraphical units are defined, whereas a corresponding subdivision of the Lower Cretaceous remains to be established.