For the determination of cellular immunity status, mitogen‐induced lymphocyte proliferation tests are used, along with measurements of cytokine secretion. The authors have established a test system with whole blood cell cultures in which they measured the following cytokines: alpha‐interleukin‐1 (α‐IL‐1), interleukin‐2 (IL‐2), gamma‐interferon (τ‐IFN), and alpha‐tumor necrosis factor (α‐TNF) in the supernatants by enzymoimmunologic methods. With this system, the authors tested blood samples of 72 patients with malignant melanoma, 38 patients with basal cell carcinoma, and 315 healthy control subjects. In the blood cell cultures of the patients with melanoma, significantly lower values of the lymphokines τ‐IFN and IL‐2 were found, compared with those of the control subjects, and the levels of the monokines α‐IL‐1 and α‐TNF were reduced. τ‐IFN values correlated with different clinical stages. In contrast, the patients with basal cell carcinoma had equal values for all four cytokines as an age‐matched control group. Cancer 1993; 71:231‐6.