There has been a renewed interest in ways of encouraging the middle classes back to the cities that many have left. Gentrification describes an interest in working class and cheaper neighbourhoods by middle class and professional households. The image of trendy Islington has done much to aid the greater currency of the term but gives us some idea of the outcome if little idea of the social costs involved. Recent research for the ESRC Centre for Neighbourhood Research sought to evaluate the relative value of gentrification as a possible route towards an urban renaissance by reviewing all empirical research on the topic for the last thirty years. The review covered more than a hundred pieces of research, predominantly from North America and the UK.