Evidence is presented that human polymorphonuclear neutrophils (PMN) can be induced to produce tumor necrosis factor (TNF). Other investigators have previously reported that TNF has been induced from macrophages by bacteria and, more recently, from natural killer cells by certain tumor cells. Our laboratory has reported that the opportunistic fungi, Candida albicans, can induce TNF, not only from human monocytes, but also from Percoll-fractionated large granular lymphocytes. We now report that incubation of PMN with C albicans for 3 hours was sufficient for detection of TNF release, and peak induction was observed at 8 to 18 hours. This release was inhibitable by actinomycin D, an inhibitor of RNA synthesis, as well as by emetine and cycloheximide, which block protein synthesis. The TNF produced by PMN was neutralized by specific monoclonal antibodies against human TNF. These results represent an important finding that TNF production is a normal response of PMN to stimulation by fungi such as C albicans and suggest that the release of TNF may be related to autocrine activation of PMN effector function to control Candida growth.