The utility of vascular endothelial growth factor (VEGF) concentrations in serum as a predictive marker for AIDS-KS was studied. Sera were obtained from 40 homosexual men who seroconverted for HIV-1 and HHV8 prior to or during their participation in the Amsterdam Cohort Studies (1984-2000). We designed an ELISA to detect VEGF and measured VEGF prior to either infection, at HIV-1 and HHV8 seroconversion, after both infections, at AIDS-KS diagnosis (n = 11), and in the most recently available serum sample. The geometric mean serum VEGF concentration was 81.5 pg/ml in those with AIDS-KS and 80.4 pg/ml in those with AIDS but without KS. Median serum VEGF concentrations did not differ between the time points described above. Higher VEGF concentrations in serum were observed at higher CD4(+) cell counts. Serum concentrations of VEGF were not influenced by HIV-1 or HHV8 infection or by the conditions leading to AIDS-KS. Sequential measurement of VEGF in serum is not expected to contribute to the prediction or therapeutic monitoring of AIDS-KS.