Philosophers who write about blame tend to focus on angry confrontations, but in this article I look closely at the less visible, longer lasting, and seemingly more insidious side of blame: grudges. After offering an extended example of grudge-holding and surveying the scant literature on this topic in both psychology and philosophy, I offer an account of what it is to hold a grudge. On my account, grudges involve negative feelings toward a transgressor that are (1) antagonistic, (2) easily reactivated, (3) persistent, (4) globalist, and (5) not-yet-overcome. The article is dedicated to fleshing out and justifying these components, and showing how the account fits with existing research on forgiveness and related notions. I conclude by suggesting that theorists of responsibility would benefit from broadening their gaze beyond blame and forgiveness to the more general notions of holding against and letting go.