Hypoxia as a microenvironment is essential for the development of neural stem/progenitor cells (NSCs/NPCs). Our previous studies showed that mild hypoxia can promote proliferation of NPCs. However, the underlying mechanisms are remaining unknown. In the present study, we explored the impact of hypoxia on miR-210 secretion and its effect on cell viability. We found that short time or long time of hypoxia treatment could increase the expression of miR-210, but also promoted its secretion into the medium. The results of exosomes isolation and quantitative real-time PCR showed that hypoxia increased the levels of miR-210 in the exosome enriched from the medium. In addition, the secreted miR-210 can be absorbed by recipient NPCs. The resutls of cell viability assay showed that low levels of secreted miR-210 slightly increased cell viability of NPCs. In contrast, high levels of secreted miR-210 exhibited an inhibitory effect on cell viability. These effects were blocked by an miR-210-specific inhibitor. Taken together, hypoxia increased secretion of miR-210 in exosomes and exhibited a differential effect on cell viability of recipient NPCs.Video abstract: http:/links.lww.com/WNR/A588.