The impact of Squamous cell carcinoma antigen (SCC) in the follow-up of patients with cervical cancer treated with radiotherapy was evaluated. 72 patients with a histologically proven squamous cell carcinoma of the uterine cervix were treated at the Department of Radiotherapy and Radiation Ocology, Munster, Germany. The pretherapeutic serum level of SCC was elevated in 60% of patients (cut-off-level: 2.5 ng/ml). The median serum level correlated with the tumor stage. After the end of radiation treatment, 98% of patients in complete remission and 87% of patients in partial remission had a serum level below the cut-off. In the case of recurrent disease, 71% of patients had a significant increase of SCC serum levels before clinical manifestation of relapse. The leading time ranged between one and 16 months (median: 3.1 months). In conclusion, SCC is a useful tumor marker in the follow-up of patients with squamous cell carcinoma of the uterine cervix.