Abstract: A total of 18 plant extracts from the Mediterranean area were screened for acaricidal activity against the spider mite Tetranychus urticae Koch. eggs, deutonymphs and adults using a leaf disc bioassay method. Results showed that all extracts were ineffective against the egg stage and caused less than 30% mortality. Three plant extracts resulted in mortalities exceeding 50% against the deutonymph stage. These were Ruta chalepensis L. (65%), Astragalus oocephalus Boiss (55%) and Urtica pilulifera L. (51%). On the other hand, six plant extracts resulted in mortalities more than 50% to the adult stage. The highest mortality of 65% was achieved by treating adults with the extract of Phlomis syriaca Boiss. followed by Achillea biebersteinii Afan. (64%), R. chalepensis and Ballota undulate (Ghassa) (53%), Alkanna strigosa Boiss. and Hohenh. and A. oocephalus (52%). Further concentration response trials showed that the LC50’s values for the extracts of R. chalepensis, A. oocephalus and A. strigosa were 8.5, 9.9 and 10.8% wt/wt, respectively. These results indicate that the extracts of R. chalepensis, A. oocephalus have the potential to be developed as botanical acaricides for eco-friendly management of T. urtica.