In a recurrent noninvasive papillary carcinoma of the bladder, cytogenetic analysis by the direct technique was carried out on cystoscopic biopsies obtained at 53 mo. intervals. Persistent similar karyotypic abnormalities including aneuploidy, ring and other marker chromosomes, the hallmarks of invasive cancer, were present in both specimens. In the 1973 specimen, DNA banding was identified in 35% of the metaphases and in 56% of the karyotypes. The continuing abnormal chromosomal silhouette of this tumor supports the stemline cell concept for malignancies, even when applied to such relatively benign neoplasms as this noninvasive carcinoma of the bladder.