The soils of the Parque Natural da Arrábida are surveyed along four "catenae" right across the Parque. Dominant soil formating processes and their regional importance are shown. The soils are described as units according to FAO (1988). On the basis of the FAO units an attempt is made to combine soil units with ecological classes. A comparison with the soil map 38-B and the portuguese classification (Cardoso 1964) is given. Unfortunately it is not possible to transform the units of that map into soil units according to FAO (1988).