Twelve normal, healthy adult individuals, 9 men and 3 women, 25-48 years of age (mean, 38 years), were recruited in the study. After 12 hours of fasting, blood specimens were collected at 8:00 AM for prostaglandin E(2) (PGE(2)), PGF(2alpha), and thromboxane B(2) assays. Each individual then drank 250 ml of water containing 1.2 g/kg body weight of natural unprocessed honey, after which collection of blood was repeated at 1, 2, and 3 hours for estimation of prostaglandins. Each individual was asked to drink the same amount of honey diluted in water once a day for a maximum of 15 days. After 12 hours of fasting, morning blood specimens were collected on day 16, and plasma prostaglandin concentrations were measured. The quantitative analysis of prostaglandins was performed with use of an enzyme-linked immunosorbent (ELISA) test. Results showed that the mean plasma concentration of thromboxane B(2) was reduced by 7%, 34%, and 35%, and that of PGE(2) by 14%, 10%, and 19%, at 1, 2, and 3 hours, respectively, after honey ingestion. The level of PGF(2alpha) was decreased by 31% at 2 hours and 14% at 3 hours after honey ingestion. At day 15, plasma concentrations of thromboxane B(2), PGE(2), and PGF(2a) were decreased by 48%, 63%, and 50%, respectively. It may be concluded that honey can lower the concentrations of prostaglandins in plasma of normal individuals.