The toxicity of some common plant extracts towards workers of three species of Pheidole ants was evaluated under laboratory conditions. Methanolic extracts of nine plants indigenous in Egypt, were examined for their potential use as alternatives to synthetic chemical pesticides. Extracts of the tubers of Allium sativum L., the seeds of Anethum graveolens L., Coriandrum sativum L., Trigonella foenum-graecum L and Nigella sativa L., flowers of Calndula officinalis L., and leaves of Mentha viridis L., Rosamarinus officinalis L and Eucalyptus citriodora Hook were tested in this way. Bioassays were performed on mature workers of three species of Pheidole ants; P. jordanica (Saulcy), P. laticeps (Mayr) and P. sinatica (Mayr) (Hymenoptera: Formicidae) also common in Egypt. All crude methanolic plant extracts exerted toxic effects on workers of the three Pheidole species. The crude methanolic extract of A. sativum was the most effective, as indicated by the highest percentage mortality of ant workers, followed by extracts of T. foenum-graecum, while crude extract of E. citriodora, showed the least activity. The results indicate the potential use of some of these plant extracts as a source of safe alternatives to insecticides.