This study was conducted to determine pregnant women's exposure to third-hand smoke, beliefs and influencing factors. The study included 400 pregnant women in a tertiary care obstetrics and gynecology hospital in Turkey. Data were collected using personal information form, Beliefs About Third-Hand Smoke Scale (BATHS-T) and Fagerström Test for Nicotine Dependence. 13.5% of the pregnant women smoked during pregnancy. However, 78.8% of the pregnant women were exposed to cigarette smoke at home. The mean score of BATHS-T scale and sub-scales increased in those whose spouses had university education or higher, and in pregnant women and their spouses who were public employees. The mean scores of BATHS-T scale and sub-scales were higher in pregnant women in the first trimester of pregnancy and in pregnant women with higher income levels. Community-based awareness of the effects of first, second and third-hand exposure to cigarette smoke on maternal and fetal health should be increased.