Considering the fact that urbanization is one of the most serious threats to geodiversity, it is important that this issue is taken into account in spatial development plans and georesource management strategies in urban areas. This paper presents the application of a geodiversity evaluation method by using the geodiversity index, based on the quantity of abiotic elements and relief roughness within a spatial unit. Geodiversity assessment, usually used for remote, protected and sparsely populated natural areas, is now carried out in an urban environment – the city of Belgrade, capital of Serbia, with a population of about 1.7 million inhabitants and very strong urbanization in the last few decades. The area of 3227 km2 is processed with the spatial resolution of 1 x 1 km. The acquired results from the geodiversity index are analyzed in the context of sustainable use of georesources and the threats to which geodiversity is exposed due to the territorial expansion of the city. The mapping of specific categories of geodiversity on the basis of quantitative assessment with the use of Geographic Information Systems can help decision makers and managers to take further steps that would reduce threats and protect the natural value of Belgrade.