Smoking in pregnancy is unhealthy and can also have negative effects on the foetus. However, there are still some women who do not quit smoking during pregnancy. The aim of the study was to identify Slovenian women at risk who smoke during pregnancy. A quantative approach using an online survey was adopted. The study was conducted in May and June 2017, in Slovenia. A snowball sample was used. Participation in the survey was anonymous and voluntary, and 118 women who identified themselves as smokers participated in the study. Descriptive statistics was used to analyse the data. More than half (66%) did not quit smoking during pregnancy. Women who continued to smoke during pregnancy were usually younger, less educated with a partner who smoked. Women who smoked more cigarettes per day before conception were less likely to refrain from smoking during pregnancy. The most common reason for not quitting smoking during pregnancy was failure in attempts to quit (37%). Women who smoke need support to stop smoking before pregnancy or, at least, in the first trimester. Special groups for smoking cessation need to be created. Further and more extensive research is warranted in Slovenia to assess this issue.