Environmental planning is fundamental for the sustainable developement of cities. In the case of Matinhos, on the Paranánese coast, as well as other Brasilian municipalities, this planning was neglected. For this reason, urban settlements can be found in areas which are actually considered areas of permanent preservation (APP), according to the Forestry Law. The present article describes the preliminary results of a mapping study of the urban occupation, especially in APP along the river line, where under natural condition one would find a riparian forest. The riparian environment has great ecological importance for the river and the preservation of its quality. The ccupation of these areas brings consequences for the substituition of this natural vegetation by other cover, for example, impermeable areas or areas of exposed soil.