Summary:  Notch signals regulate multiple cell fate decisions during metazoan development. During hematopoiesis, Notch affects both hematopoietic stem cells and committed progenitors. In hematopoietic stem cells, Notch signaling has the propensity to expand the stem cells, promote their self‐renewal, and influence their survival. In committed progenitors, Notch signaling plays a key role in determining lymphoid cell fates. This review focuses on recent developments to understand the role of Notch signaling in early events in hematopoiesis.