Increased serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), soluble endothelial leucocyte adhesion molecule-1 (sELAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were detected in Danish malaria patients infected with sequestering Plasmodium falciparum or non-sequestering P. vivax parasites, as well as in patients with sepsis or meningitis. Levels of soluble adhesion molecules remained elevated in the P. falciparum patients for several weeks after initiation of treatment. Plasma concentrations of sICAM-1, sVCAM-1 and sELAM-1 were higher in Gambian children with severe P. falciparum malaria than in children with mild malaria. Plasma levels of sVCAM-1 and sELAM-1 were significantly correlated. Plasma levels of sELAM-1 and sVCAM-1 may reflect endothelial inflammatory reactions and these reactions may be harmful for humans infected with malaria parasites.