It has been almost 30 years since the metaphor of the glass ceiling was coined to describe the often subtle, but very real, barriers that women face as they try to climb the organizational hierarchy. Here we review evidence for a relatively new form of gender discriminationcaptured by the metaphor of the glass cliffthat women face when they obtain positions of leadership. Such positions often prove to be more risky and precarious than those of their male counterparts. We summarize evidence demonstrating the existence of glass cliffs in business and politics as well as experimental work that identifies a number of factors contributing to the phenomenon. We then discuss implications for policy and practice, highlighting the importance of understanding women's and men's experiences in the workplace rather than treating gender diversity as merely a numbers game.