Why do so many people fail to manage their emotions successfully even though they can do so? This review begins by noting that the gap between emotion regulation ability and achievement is a consistent yet surprising finding across individuals with emotional disorders, many of whom appear to be able to effectively regulate emotions when cued. Recently, clinical science has begun to take stock of this puzzling gap between intact emotion regulation ability and challenges with emotion regulation achievement. We refer to this as the ‘emotion regulation ability-achievement’ gap, and discuss clinical implications, including alternative approaches to closing this gap.