The evidence of an association between childhood exposure to environmental tobacco smoke (ETS) and an increased risk of lung cancer is inconsistent. However, taking into account the existing association between lung cancer and adulthood ETS exposure, it is plausible that children exposed to ETS also would be at risk of developing lung cancer later in life. In this study, we investigated the uptake by Moldovan children of the tobacco-specific lung carcinogen 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) by measuring total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), the sum of the NNK metabolites, NNAL, and its O-glucuronide and N-glucuronide (NNAL-Glucs) in urine. We also measured urinary cotinine and its glucuronide (total cotinine). Total NNAL was detected in 69 of 80 samples, including those that were low in cotinine (<5 ng/mL). The mean ± SD level of total NNAL (0.09 ± 0.077 pmol/mL) was comparable with those observed in previous studies of children and adults exposed to ETS. Total NNAL correlated with total cotinine (r = 0.8, P < 0.0001). The mean ± SD levels of total NNAL and total cotinine were higher in children who were exposed to ETS (0.1 ± 0.08 and 109 ± 126 pmol/mL, respectively) than in those who were classified as unexposed to ETS based on questionnaire data (0.049 ± 0.016 pmol/mL and 0.043 ± 0.040 nmol/mL). The results of this study for the first time show widespread and considerable uptake of nicotine and the tobacco-specific lung carcinogen NNK in Moldovan children. These results should be useful in heightening the awareness of the dangers of smoking and ETS exposure in this eastern European country.