We performed environmental burden of disease (EBD) assessment of the neurotoxic effects of lead in the Polish urban children, in accordance with the WHO guidelines. The EBD assessment was based on the data on blood lead levels (BLL) of more than 8500 children from the lead biomonitoring programme conducted in the urban centre of the Upper Silesia Province, Poland between 1993 and 2000. In order to make the EBD assessment region specific, in the projections to years 2001 and 2005 we used 4% annual decrease in BLL, derived from the earlier analysis of the Silesian BLL data instead of the WHO proposed 7.8%. Mean BLL in the Silesian children projected for the year 2001 was higher (4.9 microg/dL) than the corresponding value for the WHO EurB region (3.9 microg/dL). The incidence rate of mild mental retardation (MMR) in the Silesian children was twice as high as in the EurB region for the year 2001, meaning more than two additional cases of MMR due to lead exposure per 1000 children aged 0-1 year, compared with 1 in 1000 children in the EurB region.