An increased mortality has been reported during long-term etomidate infusion. Inhibition of adrenal corticosteroid synthesis has been incriminated - but other factors related to host defence cannot be excluded. Using an under-agarose assay, we investigated the effect of etomidate on in vitro granulocyte migration. Unlike thiopental (50 micrograms/ml), etomidate (4-32 micrograms/ml) did not affect either spontaneous or directed migration. Impaired granulocyte migration is an unlikely cause of morbidity during long-term etomidate infusion.