With the current converging trends of urbanisation and population aging, but also shifting of the age limit for active aging and virtualization of daily activities, it is important to focus attention on the most vulnerable groups of citizens living in urban areas, who, in a rapidly changing world, face the threat of loneliness and isolation due to the degradation of physical or psychological health, social or cultural isolation, barriers in space, technological and communication barriers and the like. Seniorfriendly approaches in spatial planning concern mainly seniors (or persons at the end of an active life), but there are natural overlaps also towards the needs of other groups with specific needs, as well as other persons of every social inclusion. The article summarizes the key opinion making institutions efforts (mostly United Nations and WHO) to help cities on their way to build an environment more friendly to older people, to facilitate the exchange of experiences and provide them with a supportive framework, and focuses on zooming in on the content of the WHO manual Measuring the Age-Friendliness of Cities. A Guide to Using Core Indicators, which represents a helpful tool for setting policy frameworks for cities by indicating a set of core and additional indicators for monitoring and evaluating progress in the friendliness of the urban environment to age. The manual was created in 2015 as the result of a structured preparation process with inputs generated from more than 40 communities across 15 countries, and a final pilot study involving 15 communities across 12 countries.