This study was conducted to investigate the serum levels of bcl-2 and survivin in patients with melanoma and the relationship with tumour progression and known prognostic parameters. Forty-four patients with cutaneous melanoma were investigated. Serum samples were obtained on first admission before adjuvant and metastatic treatment were given and at follow-up. Serum bcl-2 and survivin levels were determined using enzyme immunometric assay (EIA) and enzyme-linked immunosorbent assay (ELISA). The baseline serum bcl-2 levels were significantly higher in patients with melanoma than in the control group (P=0.01). For the serum survivin levels, no difference was found (P=0.6). No significant correlations were found between the prognostic parameters analysed and the serum survivin concentrations. The same was true of the serum bcl-2 values, except for the age of the patient (P=0.025) and nodal involvement (P=0.003). No significant relationship was found between the serum levels of bcl-2 and survivin (r=-0.13, P=0.4). In node-positive patients (n=8) both of these anti-apoptotic substances were unchanged after interferon-alpha-2b therapy. However, serum survivin concentrations were significantly increased in 10 patients with metastatic melanoma who underwent dacarbazine (DTIC)-based cytotoxic chemotherapy (P=0.047). A similar finding was not determined for the serum bcl-2 levels. In conclusion, the results of this study suggest that decreased apoptosis is associated partly with an increase in serum bcl-2. However, much research continues in this field, and exciting new knowledge will ultimately emerge.