In this study, chromosomal damage induced in vitro by lead acetate in human melanoma cells (B-Mel) was evaluated using the cytokinesis-blocked micronucleus assay and sister chromatid exchange (SCE) analysis. Lead acetate (10-6, 10-5 and 10-3 mM) induced micronuclei and SCE formation in a dose-dependent manner. Treated cells showed a decrease in cell viability but not concomitant cell death by apoptosis (lead acetate failed to induce internucleosomal DNA fragmentation at any of the doses tested). One important observation emerging from this study was that low-level lead exposure in vitro is able to induce significant cytogenetic damage in human melanoma cells, indicating an increased sensitivity of B-Mel cells to lead acetate.