Although lacking official recognition from the urban authorities, the urban network of alleyways still houses about 85% of city dwellers in Ho Chi Minh City. As such, it remains an important ingredient of the Vietnamese urban identity. The anthropological exploration of the daily functioning of ordinary alleyways of Ho Chi Minh City provides an invitation to acknowledge the social value of ephemeral public spaces, which are constantly renewed by residents’ uses and interchanges. These fluid and shifting spaces allow for a great reversibility in urban functions and illustrate the idea of the street as a ‘capital for experimentation’ and the fruit of a social agreement continuously renewed over time, which allows both for the permanence of a spatial form and the modification of its parallel uses. Beyond the antagonism of the public/private duo inherited from the Western conception of urban spaces, Vietnamese alleyways offer the richness of the buffer zone of its intermediate semi-public spaces, at the interface of the tube-house and the street. In Vietnam, the level of publicness of a space varies depending on the time of day, and day of year. This remark invites us to re-think the notion of public space from the perspective of Ho Chi Minh City alleyways, in order to fully integrate the urban practices and conceptualisations of the global South in the field of urban theory.