A new sandwich antigen enzyme-linked immunosorbent assay (ELISA) for the detection of Aspergillus galactomannan in blood plasma was compared with the latex-agglutination test by investigation of six patients with histologically proven invasive aspergillosis. The ELISA gave positive results in all six patients while the latex test recognized 5/6 as positive. On an average the antigen ELISA gave positive results 19 days earlier than the latex test.