Free phenolic compounds was extracted by ethyl acetate from olive oil mill wastewater. Extraction yield was 50 mg of total phenol on 100 g of wastewaters. Phenolic compounds recovered, determined by HPLC, were hydroxytyrosol (as major compound) and tyrosol, caffeic acid and ferulic acid (as minor compounds). For determination of antioxidant effects by Rancimat, phenolic extract, dissolved in distilled water, was added in different lard samples in quantity ranged between 50 and 3 50 mg kg(-1). Antioxidant effectiveness was measured also at low temperature. It was confirmed that natural antioxidants extracted from olive mill wastewater are highly effective for oxidative stabilization of lard. Cytotoxicity assay showed that wastewaters phenolic extract did not inhibit cell growth at the doses of 100-200 ppm. Thus, lard with olive phenols is a possible "novel food" for health benefit and contributes a significant utilization of olive waste water. (c) 2005 Elsevier Ltd. All rights reserved.