Stressful life events have been associated with preterm delivery in some studies but not in others. One cause of this inconsistency may be that different life events have different effects. The author used data collected by the Pregnancy Risk Assessment Monitoring System, a survey of American women with a recent live birth, for 1990–1995 to examine the relationship between individual life events and the risk of preterm delivery overall and by levels of severity. Four events of the 18 examined were associated with an increased risk of at least one category of preterm delivery: being in debt, being injured by a partner, having someone close attempt suicide, and being divorced. Women who reported being in debt had an increased risk of preterm delivery overall and for each level of severity. One event, having a partner who lost his (or her) job, was associated with a decreased risk of preterm delivery. These results provide some support for the theory that increased stress from life events causes preterm delivery. The lack of a pattern by type of stress, expected stressfulness, or severity of prematurity are hard to reconcile with those theories, however.