Despite rapidly increasing contraceptive use and rapidly declining fertility, unintended pregnancy and induced abortion remain common in Vietnam. This study reassesses the level of unintended pregnancy in Vietnam and its correlates, drawing on retrospective calendar data gathered for the Vietnam Demographic and Health Survey II. Data from 13,540 “segments” of outcomes and contraceptive practice were analyzed. Based on the calendar data, 40 percent of pregnancies during the 1994-97 period are estimated to have been unintended, a proportion 48 percent higher than the prevailing estimate calculated from the reported intendedness of live births. When concealment of pregnancies ending in induced abortions is taken into account, the unintended pregnancy rate in Vietnam is likely to approach levels found only in developing countries. Unintended pregnancy was found to be associated with age, early marriage, spousal age difference, number of living sons, past unintended pregnancy, geographic region, contraceptive use prior to pregnancy, and the family planning supply environment. The findings suggest that broadening the method mix at the community level, targeting high-risk and underserved groups, and expanding postabortion counseling and services are likely to have a dramatic impact on the unintended pregnancy rate in Vietnam.