Among the complex and articulated molecular mechanisms activated by hypoxia, microRNAs play a central role. Specifically, this Forum is dedicated to hypoxamiRs, defined as microRNAs that not only are directly regulated by hypoxia but also regulate cell responses to decreased oxygen tension. We assembled a collection of reviews and research communications by authoritative leaders in a variety of disciplines, describing hypoxamiRs from different angles. Fundamental technical issues as well as hypoxamiR impact on general events, such as metabolism and development, are critically reviewed. The regulation and the role of hypoxamiRs in cardiovascular diseases and in cancer are also addressed. An increased understanding of the function of hypoxamiR in gene regulatory networks of great physiopathological relevance may allow the development of innovative therapeutic approaches for all ischemic diseases.