We present the data of 105 serum samples from 20 patients suffering from cervical cancer. Mean serum levels of basic fibroblast growth factor (bFGF) in patients with or without tumor present were 31.3 +/- 32.1 (minimum 0, maximum 156.7) pg/ml and 4.8 +/- 6.8 (minimum 0, maximum 29.6) pg/ml, respectively (P = 0.0001). bFGF reached a sensitivity of 65.7% at a specificity of 91.5% when applying a cut-off level of 15 pg/ml. Four patients relapsed after complete remission. A continuous increase of bFGF serum levels before the clinical detection of relapse (lead time) was seen in two cases with a mean lead time of 4 months. Preoperative serum levels were not of prognostic value and showed no correlation with pelvic lymph node metastasis. These preliminary results indicate that in cervical cancer patients soluble bFGF may be useful in early detection of primary tumors, recurrences and monitoring of therapy.