Recently serum S-100beta has shown promise as a tumour marker in melanoma; however, its use as a prognostic marker in the advanced stage needs to be confirmed. Interleukins (ILs) may mediate regression or progression of cancer. In order to study their relation to the metastatic profile and survival, we evaluated the association between pretreatment serum levels of S-100beta, IL-6, IL-10 and IL-12 and metastatic site and survival in 50 patients with advanced melanoma who were to receive chemoimmunotherapy. Patients with liver and/or bone metastases had significantly higher median concentrations of S-100beta, IL-6 and IL-10 than those with only skin, nodal and/or lung involvement. The differences in IL-12 levels were unremarkable. Using univariate analysis, the S-100beta level and metastatic profile were found to be statistically significant prognostic factors for survival. Using multivariate analysis the S-100beta level was the most powerful prognostic indicator, while the metastatic profile was found to be significant after exclusion of S-100beta. The findings suggest that elevated serum levels of S-100beta, IL-6 and IL-10 reflect concurrent liver or bone metastases in melanoma. S-100beta is also an independent prognostic marker. Pretreatment IL levels were not associated with outcome.