Sustainable development is currently a very up-to-date topic, the understanding and use of which has now gone further from its initial — environmental association. This paper is focused on one of the “youngest” kinds of sustainable development which is social sustainability. Its key elements are social inclusiveness, equality, access to education, diversity and safety, as well as good social capital — among others. As the most vague and human-related kind of sustainable development, it causes discussions on its measurement and international comparability. The example of Medellín, a Colombian city awarded for its innovativeness, is presented to discuss social sustainability measurement on the city level. This example proves that social sustainability tools are most useful when related closely with the social policies, which at the city level is fully doable.

Medellín, a city in Colombia, is known for its resurrection from the status of the most dangerous city in the world to that of the most innovative one (awarded in 2013). The paper discusses the achievements of Medellín as a Smart City, which include, among others, the popularisation of Internet usage, optimisation of the urban transportation system with a reduction in traffic accidents, development of a mass transportation system with a cable car for a famous city in the developing world, improved security, together with an efficient crime reporting system and environmental risk monitoring. The potential risks involved in the implementation of ICT in city management are also discussed, related mostly to social exclusion and the actual distribution of the benefit coming from the Smart City. When compared with European cities, the additional barriers that the Colombian city needs to overcome are very high social inequalities, endemic crime, and topographic difficulties. This Latin American perspective can make clearer the difference between the Smart City in cities of the Global North vs Global South.