Various studies indicate that the soluble interleukin-2 receptor (sIL-2R) is of value as marker in chronic and malignant disorders. No data are available on sIL-2R levels in head and neck cancer. The serum of 86 patients with squamous cell carcinoma of the head and neck (SCCHN) prior to any therapy and of 25 healthy controls was taken. Six month later the serum of 49 patients was taken again. sIL-2R levels were determined with ELISA. Patients with SCCHN prior to therapy had significantly elevated sIL-2R serum levels (895 U/ml) compared to controls (437 U/ml). After an eight month follow up 78.4% of the SCCHN patients with tumor recurrence had increased and 80% of the carcinoma patients without recurrence had decreased sIL-2R levels compared to prior to therapy. sIL-2R seems to be an unspecific marker for SCCHN and may be of prognostic value.