The results of round 13 of the Environmental Lead Proficiency Analytical Testing (ELPAT) program were discussed. ELPAT is a program administered by the American Industrial Hygiene Association (AIHA) in cooperation with NIOSH and the Office of Pollution Prevention and Toxics, Environmental Protection Agency to evaluate and improve the performance of laboratories performing analyses associated with lead (7439921) abatement. Any interested laboratory can participate in the program. Proficiency test samples for the participants were prepared by the Research Triangle Institute using paint chips, dusts, and soils. Four samples of each matrix were prepared. The samples were sent out each calendar quarter (round). The laboratories were rated based upon their performance in the ELPAT program over the past year (four rounds) for each lead matrix: paint chips, soil, and dust wipes. A laboratory was rated as proficient for a specific lead matrix if all four results were reported and all were designated as acceptable for the last two consecutive rounds or at least 75% of the results reported in the last four consecutive rounds were judged acceptable. A total of 402 laboratories participated in round 13 which was sent out in November 1995. Of these, 371 submitted results. The percentage of outliers in the reported data for each lead matrix were: paint chips 3.3 to 9.3%, soils 3.2 to 7.3%, and dust wipes 3.2 to 7.9%. The percentage of laboratories that were judged proficient for each matrix were: paint chips 94%, soils 95%, and dust wipes 95%.