According epidemiological study tobacco smoking is popular addiction around the world. It was estimated, that one third of world population smoking tobacco. The statistical data from 2002 show that in Poland 42% of men and 22% of women smoke tobacco on a daily basis. As many as 60% of non-smokers are exposed to environmental tobacco smoke (ETS). The aim of the study was verification the answer on a standardised survey questionnaire (related to tobacco smoking) by laboratory method--determination of cotinine in urine. In the study participated 244 delivering women. In the tested group 23.8% of surveyed declared smoking during their pregnancy and around 28% of non-smoking women were exposed to passive inhalation of tobacco smoke. More than 15% of women, which declared non smoking has concentration of cotinine higher than 50 ng/mg creatinine (mean 227.3 ng/mg creatinine) what indicated active smoking of cigarettes. From these results we can conclude that as much as 35.6% of women smoking tobacco during pregnancy and is higher than suggested the questionnaire examination.