Eight plant species of eight genera were chosen from eight plant families to initiate a screening programme designed to discover potential anti–tumour activity contained in plants of the Egyptian flora. Of the eight plants only three showed definite cytotoxic effect namely Hedera helix Linn., Prosopis juliflora D. C. and Cätharanthus roseus G. Don. The extract of the last had the best anti–neoplastic activity against Ehrlich ascites carcinoma cells as measured by a simple screening scheme which proved quite adequate and reliable.