The problems are presented of the Lower Tortonian (Opolian substage) littoral structures in the Miechów and Cracow Uplands of southern Poland. Particular littoral structures are described giving i.a. detailed characteristics of various lithophags. The importance is pointed out of these structures for the reconstruction of pre-Tortonian morphology and for the palaeogeography of the Tortonian transgression onto the Miechów and Cracow Uplands. The development of the marine basin which resulted from this transgression in both areas is presented