Background: Exposure to contaminant mixtures in developing countries is an important public health issue. Children are identified as the most susceptible group to adverse health effects due to the exposure. Objective: The aim of this study was to conduct a screening for mixture pollutants in Mexican children in urban marginalized communities. Methods: We analyzed children (aged 6-12 years old) who resided in four urban marginalized communities in San Luis Potosi, Mexico: i) Bellas Lomas (BEL), a site with vehicular traffic; ii) Tercera Chica (TC), a site with brick kilns; Iii) Rincon de San Jose (SJR), a site with a hazardous waste landfill; and (iv) Morales (MOR) a metallurgical zone with copper-arsenic and electrolytic zinc smelters. Polycyclic Aromatic Hydrocarbons (1-hydroxypyrene (1-OHP)), benzene (trans, trans-muconic acid (t,t-MA), manganese, arsenic and fluoride were quantified in urine and lead in blood samples. Findings: Our results indicate that median exposures to manganese were 4.4, 5.2, 5.8 and 6.3 µg/L for BEL, TC, SJR and MOR, respectively. For BEL, fluoride was present at a higher concentration with 2.3 mg/L followed by MOR, TC and SJR with 1.7, 1.5 and 1.2 mg/L respectively. The highest concentrations of arsenic that were found were 11 µg/L in MOR and lead concentration was reported between 4.2 and 6.8 µg/dL, in BEL, TC and MOR. 1-OHP and t,t-MA were higher in TC (0.23 µmol/mol creatinine (cr), 429.7 µg/g cr, respectively) followed by SJR (0.09 µmol/mol cr, 427.4 µg/g cr), MOR (0.03 µmol/mol cr, 258.6 µg/g cr) and BEL (0.06 µmol/mol cr, 220.6 µg/g cr).