This study investigated the prevalence of elevated blood lead (PbB) levels in children 1-6 years old in Kaduna, a medium size city in northern Nigeria. Mean PbB was found to be 10.6 micrograms/dl, and 2% of the children had PbB levels greater than 30 micrograms/dl. Highest average PbB levels were found in children 5 years old and was attributed to the tendency for this age group to play longer in contaminated outdoor environments. The strongest associations were found between PbB and whether the family owned a car or lived in a house on a tarred road. Potential sources of lead in the city as well as household and behavior risk factors likely to result in exposure of children to lead are discussed. This study provides additional data pointing to childhood lead poisoning as being a major public health problem in urban areas of Africa.