This study examined the process of change in pregnancy smoking cessation, using the stages and processes of change from the Transtheoretical Model, to compare women who stopped smoking during pregnancy with women who were in the process of smoking cessation, but were not pregnant. Differences in smoking cessation process activity and abstinence self-efficacy were hypothesized between the pregnant and nonpregnant groups of women. Study participants were 89 pregnant women who quit smoking, 28 nonpregnant women in the action stage of smoking cessation, and 92 nonpregnant women in the preparation stage. The Smoking Cessation Processes of Change Scale and the Smoking Abstinence Self-Efficacy Scale served as dependent measures. One-way MANOVA and follow-up Newman-Keuls comparisons indicated significant differences between pregnant and nonpregnant women in their levels of process activity and self-efficacy. Pregnancy smoking cessation differed dramatically from the process of nonpregnancy smoking cessation. Pregnant quitters were not engaging in experiential and behavioral processes at levels associated with the action stage of change. Low levels of process use and high efficacy indicated an externally (for the baby) motivated stopping rather than an internal, intentional process of change, which may account for high relapse rates postpartum.