Modern society is becoming an exclusively urban society. The urban population is steadily increasing, which results in decrease of population in rural areas. Even the rural population, imposed with the new and modern way, is undergoing a transformation and its life becomes urban. The aim of this paper is to show characteristics of urbanization in developing and underdeveloped countries, but also its impact on the ecological sustainability of the entire system. Ecological sustainability is increasingly present with the appearance. It signifies the ability to maintain certain conditions and phenomena, but also to bring harmony to the human environment in which it resides. All those activities that disturb the harmony between man and nature, which lead to a direct decrease in the quality of the future generation, will be defined. The degree of urbanization of the Republic of Croatia with the dynamics of urbanization development will be analyzed as well as a comparison with individual countries of the European Union. Due to major problems that come with urbanization, the European Commission has launched the "URBAN" initiative, which is based on a pilot project in all areas of sustainable urban development. There are major challenges in terms of migration, employment, demographics and environmental issues such as soil, water and climate change. The Union's 2020 Community Action Program "Living well within the confines of our planet" has been accepted by the European Parliament and the Council, so this paper will analyze all its key parts and priority objectives. The last chapter dealt with a comparative analysis of the selected EU country on waste recycling through available figures for individual countries. In conclusion, it was found that the development of the country has as impact on waste recycling.