Abstract. This paper presents a methodology for assessment of geomorphosites located in protected areas. The methodological process involves definition of «geomorphological value» of all sites using six criteria: 1) «scientific» and «educational value»; 2) geodiversity, 3) «ecological» and «aesthetic value»; 4) «cultural value»; 5) potential threats and protection needs; and 6) potential for use. The assessment method was implemented in Greece on various geomorphosites at different scales: landscape scale (national parks and monuments) and landform scale (Lesvos Island Geopark). For this purpose, eight representative national parks and natural monuments were classified and assessed using the proposed methodology at a large scale. The same methodology was also used to evaluate 15 distinet geomorphosites found in the coastal zone of the Lesvos Petrified Forest Geopark. Here, geomorphosites of different sizes and categories were selected, classified and assessed. In order to protect the identified geomorphosites and ensure their proper management, the Natural History Museum of the Lesvos Petrified Forest, which is the management structure of the Lesvos Geopark, proposed the development of the Western Lesvos Marine Park. This park is to include the existing coastal visiting parks and a series of geomorphosites and marine fossil Sites.