An interlaboratory programme has been started within the Measurements and Testing Programme (formerly BCR) of the European Commission to evaluate the performance of analytical techniques used for the determination of trimethyl-lead in simulated rainwater and urban dust. A first interlaboratory study on solutions was successfully concluded in 1993 and a second exercise was organized, focusing on simulated rainwater and urban dust analysis. This paper reports the results of this second interlaboratory study, which is a preparatory step for a certification campaign of simulated rainwater (with representative contamination levels) and urban dust.