The present study shows that long-term, low-quality marriages have significant negative effects on overall well-being. We utilize a nationally representative longitudinal study with a multi-item marital quality scale that allows us to track unhappy marriages over a 12-year period and to assess marital happiness along many dimensions. Remaining unhappily married is associated with significantly lower levels of overall happiness, life satisfaction, self-esteem and overall health along with elevated levels of psychological distress compared to remaining otherwise continuously married. There is also some evidence that staying unhappily married is more detrimental than divorcing, as people in low-quality marriages are less happy than individuals who divorce and remarry. They also have lower levels of life satisfaction, self-esteem and overall health than individuals who divorce and remain unmarried. Unhappily married people may have greater odds of improving their well-being by dissolving their low-quality unions as there is no evidence that they are better off in any aspect of overall well-being than those who divorce. (Contains 6 tables.)