Abstract: A glucan of cellular origin has been isolated from Libyan dates (Phoenix dactylifera L.) and the structure of the purified glucan characterised using derivatisation methods including methylation, periodate oxidation and acetolysis. Glucans were found to exhibit potent antitumour activity; this activity could be correlated to their (1→3)-β-D-glucan linkages. This is the first report on studies of antitumour active compounds occurring in dates.