Smoking is one of the leading preventable causes of death worldwide. Its detrimental effects are not only seen in the smoker, but also in the people around the smoker and in the fetus of maternal smokers. The aim of this study was to determine the rates of maternal smoking during the course of pregnancy, and to identify trajectories associated with this behavior. A total of 338 pregnant women were included in the study. Participants were provided with a 20-item questionnaire on their demographic characteristics, smoking behavior and awareness of smoking harms. The smoking rate was found to be 15.7% before pregnancy and 10.6% during pregnancy. No relationship was observed between education or income level and smoking status (p=0.177. p=0.490, respectively). It was found that those participants who continued smoking during pregnancy, did not change the number of cigarettes smoked per day, or the brand of cigarettes smoked during pregnancy. In addition, the rate of passive smoking was 37%. Although the M-POWER criteria are met in Turkey, cigarette consumption remains high. In conjunction with healthcare professionals, television, the Internet, written and visual media should play a more effective role in the fight against smoking.