Squamous Cell Carcinoma antigen (SCC antigen), first described by Kato and Torigoe in 1977, has been cited as a serological marker for some epithelial neoplasms. We have evaluated the clinical significance of pretreatment and follow-up SCC antigen levels in 40 SCC patients, 15 with CIN and 5 affected by Cervical Adenocarcinomas. Serial determinations of the SCC antigen levels, carried prior to, during and after treatment, showed a hgh correlation with advanced stages (p< 0.0004) and with the clinical response to the different therapeutic treatments.