We analyzed 17 cases of dysplasia/carcinoma in situ (CIS) of the cervix and 29 advanced-stage cervical squamous cell carcinomas by comparative genomic hybridization (CGH). A comparable recurrent pattern of aberrations was detected in both preinvasive and invasive cases, although the total number of aberrations was much higher in the latter category. The most consistent chromosomal gain was mapped to chromosome arm 3q in 35% of preinvasive cases and in 72% of invasive cases. Chromosome aberrations were detected in 13/17 preinvasive cases with a total of 61 involved chromosome arms. In the invasive cases, frequent gains also occurred on 1q (45%), 8q (41%), 15q (41%), 5p (34%), and Xq (34%), and frequent losses were mapped to chromosome arms 3p (52%), 11q (48%), 13q (38%), 6q (38%), and 4p (34%). A recurrent pattern of aberrations has not previously been described in preinvasive lesions of the cervix. Our finding is surprising considering that only few preinvasive lesions are expected to progress to invasive cancer.