This study explores views on social fragmentation amongst participants from public and private high-achieving high schools in Mexico City. Whilst issues relating to social fragmentation have recently received more attention in Mexico, there is a lack of research in relation to the existing divisions amongst both school types. The paper aims to expose, through a limited sample size, some of the implications the public-private school divide represents for achieving social cohesion. From a framework of social fragmentation and private schooling in Mexico and drawing on data from semi-structured interviews, the study's findings discuss the key characteristics of high-achieving high schools, participants' conflicted views of the devalued place of public education and the current barriers for wider social interaction amongst public and private high schools. Some points for further research are suggested in the last section.