For the first time ever, more people lived in cities than in rural settlements in 2008, according to the estimations of the World Urbanisation Prospects. According to the UN projections, the future population growth will take place in cities alone. Especially the number of city dwellers in developing countries will therefore increase considerably. The urbanization ratio of the currently less urbanized least developed countries will also grow to more than 50 % by 2050. In 2008, coincidentally, the UN Commission for Population and Development covered the issues of population distribution, urbanization, internal migration and development. The challenge of rapid urbanization for developing countries was discussed in this context. The main focus was the opportunities resulting from urbanisation for the future development of the affected regions. The article analyses the important developments and trends of the current World Urbanisation Prospects and the results of the Commission for Population and Development.