Background: Studies indicate that exposure to polycyclic aromatic hydrocarbons (PAH) is associated with adverse respiratory and allergy outcomes. Exposure to PAH may impair the immune function of the foetus and, subsequently, be responsible for an increased susceptibility of children to allergic diseases. Objectives: The aim of the present study was to assess the association between mother's exposure to PAH during pregnancy and allergy diseases in their infants. We also assessed the above associations using measured PAH exposure in children's urine during the first two years of life. Methods: The current analysis was restricted to 455 mothers and their children from Lodz district. The women were interviewed three times during the pregnancy in order to collect demographic, socio-economic and medical history data. Children's health status was assessed at the age of 10-18 months and repeated at two years of age. The associations between dependent dichotomous variables and urine concentrations of 1-hydroxypyrene (1-HP) were analysed using logistic regression. Results: We showed that higher urine concentrations of 1-HP in mothers at 20-24 weeks of pregnancy increased the risk of more frequent respiratory infections (p = 0.02) in children during their first year of life. Higher 1-HP concentrations in children's urine increased the risk of food allergy (p = 0.002) in children during their first two years of life. Conclusions: This study suggests awareness of environmental factors, which may affect children's health since PAH showed to be a risk factor for airway infections and food allergy in children after adjustment for other risk factors. (C) 2016 SEICAP. Published by Elsevier Espana, S.L.U. All rights reserved.