According to certain scholars, the multicultural (global) city may constitute the ultimate site for the development of cosmopolitan sensibilities. Taken to the extreme, the assumed properties of urban life amount to a veritable 'urban alchemy': the belief that diverse and divided populations of urban dwellers may potentially be transformed into one harmonious community of cosmopolitan citizens. This paper presents an analysis of the meaning of urban cosmopolitanism to urban dwellers themselves. Heeding the calls for a more grounded, empirical approach to the phenomenon of 'ordinary' cosmopolitanisms, urban cosmopolitanism is defined as those discursive social practices in which people manage to supersede the parochialisms of their own national, ethnic and religious identities through an identification with the city. Data from 16 focus groups in London and Amsterdam demonstrate that the performance of urban cosmopolitanism was unequally accessible to people positioned differently in terms of race, class and residential status, suggesting that conceptualising cosmopolitanism as either a set of skills and attitudes or an abstract philosophy of world citizenship potentially ignores the exigencies of actual, extant cosmopolitan social practices.