The trend of increased smoking among young women has leveled off, yet 22 to 28 percent of pregnant women smoke. Aside from the usual risks of smoking, these women expose their fetuses to increased risk when they are pregnant. Pregnancy may motivate women to stop smoking because of potential adverse effects on their babies' health. A public health survey supported this claim, but no family practice studies have been reported. This is a retrospective study describing women's smoking behavior during pregnancy and at least six months after delivery. Self-administered questionnaires were given to 66 women in three family practices. Women were questioned regarding the number of cigarettes smoked before and during pregnancy and were asked their current level of smoking. Twelve women (18 percent) stopped smoking completely during pregnancy; however, of these 12, only seven (11 percent) were still not smoking at the time of the survey. Twenty-eight women (42 percent) cut down their smoking at least one-half pack per day during pregnancy. Six months to five years after delivery, only 18 of these 28 women were still smoking at least one-half pack per day less. Further study is needed to determine whether intensive antismoking efforts during routine prenatal care would be more effective and long-lasting.