This article describes a statewide, proactive telephone peer-support system to help low-income pregnant women stop smoking. From October 1994 to December 2000, 948 pregnant smokers attending the Women, Infants, Children program accepted an offer to receive support by telephone from a woman ex-smoker who called weekly, biweekly, and then monthly to provide guidance, encouragement, and reinforcement for smoking cessation. This free service, funded by the Vermont Department of Health, resulted in 25% self-reported abstinence at last telephone contact when women never reached for telephone support were counted as smokers, and self-reported abstinence during pregnancy of 20% among participants who returned for their postpartum Women, Infants, Children visit. These findings suggest that proactive telephone peer support is a viable way to help pregnant women stop smoking during pregnancy.