Squamous cell carcinoma antigen (SCC), formerly referred to as TA-4, is a tumor marker for SCC of the uterine cervix. Based on the findings in a patient with complete remission after treatment for cervical carcinoma, the authors decided to analyze the sera from patients with benign dermatoses. It was found that 83% (25/30) of the patients with psoriasis and 80% (12/15) of the patients with eczema had SCC levels in excess of the cut-off value of 2.5 ng/ml. In psoriasis the serum SCC level correlated positively with the body surface area affected by the disease (r = 0.64). Seven patients with miscellaneous skin disorders, all with an inflammatory component, showed high serum SCC levels as well. Thus the existence of an inflammatory skin disease or a hyperkeratotic skin disease with an inflammatory component interferes with the usefulness of the SCC antigen as a tumor marker in SCC of the uterine cervix.