Deletions of chromosome 1p and 19q arms are frequent genetic abnormalities in primary human gliomas and are especially common in oligodendrogliomas. However, the chromosome 1p and 19q status of many glioma cell lines has not been established. Using homozygosity mapping, fluorescence in situ hybridization (FISH), and comparative genomic hybridization to arrayed BAC (CGHa), we screened 17 glioma cell lines for chromosome 1 and 19 deletions. Sequence tagged site polymorphisms were used to evaluate the cell lines for regions of chromosome 1p and 19q homozygosity. Cell lines A172, U251, TP265, U118, SW1088, U87, SW1783, and D32 contained significant regions of 19q homozygosity. In addition, A172, U87, TP483, D37, U118, MO67, and TP265 contained significant regions of 1p homozygosity. FISH probes localized to 1p36.32 and 19q13.33 as well as CGHa were used to determine which cell lines had deletions of 1p and/or 19q. Cell lines A172, U87, TP483, TP265, H4, U251, and D37 were deleted for portions of 1p. CGHa and homozygosity mapping of these cell lines define a 700-kilobase (Kb) common deletion region that is encompassed by a larger deletion region previously mapped in sporadic gliomas. This common deletion region is localized at 1p36.31 and includes CHD5, a putative tumor suppressor gene. Cell line A172 was observed to have a deletion between 19q13.33 and 19q13.41, while U87 was observed to have a smaller deletion of 19q13.33. Cell lines A172 and U87 contain 1p and 19q deletions similar to those found in sporadic gliomas and will be useful cellular reagents for evaluating the function of putative 1p and 19q glioma tumor suppressor genes.