For the last ten years, the words ‘sustainability’ and ‘sustainable development’ have been used by many prominent political and economic leaders. But what is sustainability really and is it possible to accurately measure the sustainability of countries’ economies objectively? This study focuses on three sustainability models, namely the Environmental Sustainability Index (ESI), the Sustainability Assessment by Fuzzy Evaluation (SAFE) and the Sustainable Human Carrying Capacity (SHCC), and their evaluations on the sustainability of the Hungarian economy and environment. Furthermore, it also surveys the opinion of Hungarian undergraduate economics students on the Hungarian economy and its sustainability. The study shows that the ability of current sustainability models and measures to give accurate portrayals of countries and regions is problematic, because they use different definitions of sustainability, use different environmental and/or economic indicators, do not differentiate between the impacts of the individual indicators, and are able to be used for political purposes. This is especially true for Hungary, as the country’s economy is crumbling with increasing social unrest, yet sustainability models give it a high ranking. Also, the Hungarian students’ views on the country’s sustainability depend on what school of economics they were taught in, and what they think about Hungary’s past, current and future economic and environmental situation.