The stability of human immunodeficiency virus (HIV) antibodies was studied for samples of sera, vitreous fluid and bile obtained from eight HIV-positive autopsy cases. The autopsy delay was on average 5 days. The samples were stored at room temperature (20°C) for 51 to 314 days and tested repeatedly. In Western blotting on fresh postmortem samples, the antibodies detected most of the proteins of the virus. Antibodies against all major envelope, core and transmembrane proteins, although weakened, were also detected in stored sera. In stored vitreous fluid and bile the envelope protein gp 160, the transmembrane protein gp 41 and in half of the cases also the major core protein p 24 could still be detected. The disappearance of p 24 was associated with AIDS, but was detected in all samples from patients with early infection. Of screening tests, the enzyme-linked immunosorbent assay applying synthetic peptide as an antigen detected antibodies from all serum samples, but was less applicable to vitreous fluid or bile. Another immunoassay, applying recombinant antigen, succeeded in vitreous fluid and bile but not in sera. The rapid visually read assay detected antibodies in most samples of fresh whole blood, bile and in most of the vitreous samples, but was less useful on stored specimens.