Telecollaboration involves the use of online technologies in the context of language teaching and learning (O’DOWD, 2013). This study sought to understand how the co-construction of interculturality took place in a specific telecollaborative context - teletandem (TELLES; VASSALLO, 2006; TELLES, 2015a, 2015b). For the analysis, data from a teletandem session, a mediation session, an experience report and an interview were included. From an ecological perspective (VAN LIER, 2004; KRAMSCH; STEFFENSEN, 2008), the outcomes showed that the co-construction of interculturality was a process, that is, it occurred over time and through different instances. Put differently, instances subsequent to the teletandem session, e.g. the mediation session and the experience report, were essential for this co-construction.