<i>Background:</i> Di(2-ethylhexyl)phthalate (DEHP), the most commonly used plasticizer, is a widespread ubiquitous environmental contaminant. The potential health hazards from exposure to DEHP and its main metabolite, mono(2-ethylhexyl)phthalate (MEHP), have been well documented. Exposure to DEHP and MEHP in humans at risk, such as pregnant women and human fetuses, has not been tested. <i>Methods:</i> Plasma DEHP and MEHP concentrations were measured in a total of 24 consecutive mother-infant pairs by high performance liquid chromatography. Associations between DEHP/MEHP and infant characteristics were tested using Fisher’s exact test, unpaired t tests and univariate linear regression analysis. <i>Results:</i> Measurable DEHP and MEHP concentrations were found in 17/24 (70.8%) and 18/24 (75%) maternal plasmas, respectively, and in 11/25 (44%) and 18/25 (72.0%) cord samples, respectively. Either DEHP or MEHP were detectable in 21/24 (87.5%) maternal plasmas and 19/25 (76%) cord samples. The mean DEHP concentrations in maternal and cord plasmas were 1.15 ± 0.81 and 2.05 ± 1.47 µg/ml, respectively. The mean MEHP concentrations were 0.68 ± 0.85 and 0.68 ± 1.03 µg/ml, respectively. No significant correlations were found between maternal and cord blood DEHP, maternal and cord blood MEHP, maternal DEHP and cord blood MEHP, or maternal MEHP and cord blood DEHP plasma concentrations. <i>Conclusion:</i> Although the effects of perinatal exposure to phthalates need further research, our findings: (i) confirm the high frequency of DEHP and/or MEHP exposure in human pregnancies; (ii) indicate that the exposure to these environmental contaminants begins during intrauterine life, and (iii) suggest that fetal exposure is closely related to the maternal exposure.