Urban renewal efforts are a priority for many American cities. As efforts to reconstitute urban centers increase, the demolition of old, deteriorated structures has accelerated. Recent studies have identified demolitions as a potential source of environmental lead exposure. We conducted a study examining the relationship between demolition activity and blood lead levels of children residing in neighborhoods where demolition activity occurred. A retrospective cohort study was conducted in St. Louis City, Missouri. The study period was January 1, 2002 to December 31, 2002. Data were obtained from the Missouri Childhood Lead Poisoning Prevention Program's (CLPPP) lead surveillance system and St. Louis Demolition Permit Database. Children were considered exposed to a demolition if they had a blood lead test within 45 days of any demolition on a census block. Exposure was classified as both a dichotomous (yes/no) and a categorical (none/one/multiple) variable and was analyzed separately. Linear regression models were developed to determine effects of demolitions on blood lead levels. A total of 1196 children 6-72 months of age living in 395 census blocks were included. 314 (26.3%) were exposed and 882 (73.7%) were unexposed to a demolition. In an adjusted model, exposure to multiple demolitions was found to have significant effects on children blood lead levels (coefficient=0.281; 95% CI=0.069, 0.493; P-value=0.010). Age of the child, race, and age of housing where children's resided were also significant predictors. This study suggests that multiple demolitions within a census block may significantly increase children's blood lead levels. The findings may be useful to municipal planners in older cities where demolitions are being used as an urban renewal tool.