The Košutnjak forest in the city of Belgrade, Serbia, with an area of 259 ha, provides ecological and social benefits to its inhabitants, but its composition has changed in the last 20 years: forest areas have decreased, people have become irresponsible towards the forest and forest soil, and forest degradation is evident. The question is whether the forest has the potential to regenerate and survive. The horizontal assessment of attributes was carried out using data from the official forest database of the administrative unit “Košutnjak (2007–2016)”, which, in conjunction with the basic forest, defines indicators of change, stability, and self-renewal, which assume sustainability and can be a useful tool for sustainable forest management. The attributes and indicators are processed on a three-level alphanumeric scale in Microsoft Excel, and the data collected and analyzed are mapped using ArcGis 9.3. The ability of forests to survive without human intervention was evaluated using the EEFS method of ecological assessment of forest sustainability, which was used for the first time in this study. The results showed that forest change was significant, stability was medium, and self-renewal was low on most sections, so forest sustainability was rated as unlikely. The EEFS method used provided results that can form the basis for a forest management strategy in the city and a platform for the long-term monitoring of forest condition.