Why do young people from Generation Z (born between 1995 and the mid-2000s) become nomophobic consumers of smartphones? This research aims for a better understanding of nomophobia, the fear of being without mobile phone contact, and this from a cross-national perspective. Data collected from 1,326 young people (aged 16-24) from Brazil, China, France, and the United States demonstrate that nomophobia is positively related to materialism, the value that consumers place on the acquisition of material objects. A structural equation model shows that the different dimensions of materialism do not affect nomophobia uniformly across national identity. Nomophobia is positively related to the happiness dimension (possessions needed for happiness) in Brazil, to the success dimension (possessions as indicators of success) in China, and to the centrality dimension (possessions as central for the self) in France and the United States. These findings have notable implications for practitioners and researchers.