We use data for a survey conducted in 2006 in a comparable way across ten metropolitan cities in the developed world, and we explore the subjective perception of happiness and its association with different aspects of city life. In particular we explore which dimensions are perceived as more strongly associated to individual happiness, under a unique world-wide model of determination. We then explore whether there are deviations from this univocal pattern of association, and we provide a case-study for Milan, one of the richest and internationally oriented Italian cities. Contrary to cliché perception about Italians, Milan inhabitants express one of the lowest level of satisfaction (comparable to Tokyo or Beijing), despite their high levels of income and employment. Our suggested explanation is that the dramatic change which occurred in the last 30 years in the form and structure of the urban area (enlargement, de-industrialisation, increasing mobility, immigration, loss of population, polarisation, etc.) has brought about a worsening of the living conditions perceived by Milan’s residents.