In this study our objective was to evaluate the in vitro candidacidal effect of polymorphonuclear neutrophils of Behçet's patients with or without ocular involvement (inactive phase). Fifteen patients with ocular involvement and 15 patients without ocular involvement were studied. Candidacidal assay was performed to assess the in vitro killing of Candida species by the polymorphonuclear neutrophils of both the study and control groups. In brief, peripheral venous polymorphonuclear neutrophils of healthy volunteers and patients with Behçet's disease were obtained by density gradient centrifugation. These cells were incubated with Candida spp. (Candida albicans, Candida tropicalis, Candida glabrata) for 3 h. Samples were seeded onto yeast extract peptone dextrose agar, incubated at 25 degrees C in a 5% humidified incubator for another 48 h, and formed colonies were counted. There was no significant difference between the candidacidal activity of polymorphonuclear neutrophils of healthy volunteers and of Behçet's patients with or without ocular involvement. Although various immunological abnormalities are reported in Behçet's disease, in vitro killing of Candida spp., which is one of the parameters for the phagocytic function of polymorphonuclear neutrophils, was not affected.