The proficiency of the Environmental Lead Proficiency Analytical Testing (ELPAT) Program was evaluated for lead (7439921) in paint chips, soil, and dust wipes sent to various laboratories. Reference laboratories are preselected to provide performance limits for each sample. There were 389 laboratories enrolled for round 12 of the ELPAT Program. Agreement among the reference laboratories was demonstrated by relative standard deviations ranging from 4.8 to 9.5% for paint chips, 6 to 13.3% for soils, and 6.9 to 11.2% for dust wipes. The percentage of outliers for all samples was less than 9.9%. Statistical significance tests to detect bias among sample preparation and instrumental methods found that paint chip bias ranged from 3 to 15%, soil bias 2 to 10%, and dust wipes 6 to 26%. The ELPAT program began providing paint chip, soil and dust wipe samples to laboratories to evaluate their performance in 1992 and has grown to 300 participating laboratories. Laboratory accreditation involves submittal of a description of a laboratory's quality system and manual to the accrediting organization and an onsite evaluation. Information on how to contact the ELPAT Program was provided in the article.