Two spotted spider mite (Tetranychus urticae) is one of the most widespread and serious pests of farm and greenhouse plants. Nowadays, the use of plant essentials is considered due to the harmful effects of chemical pesticides. This study was conducted to assess the toxic potential of Yarrow (Achillea millefolium) essential oil as an effective acaricide on Tetranychus urticae on Narrow Leaf Fig plants (Ficus binnendijkii). In this study the randomized complete design was used with 8 treatments (7 treatments and 1 control). The amount of dead mites and burned Narrow Leaf Fig leaves were estimated after 24 hours. LD50 value was measured. The results showed that increasing essential oil concentrations increased the toxic effect of the essential. At the concentration of 2.5 ml* L -1, the essential caused the highest level of mortality of mites. LD50 value was estimated 1.25 ml* L -1. There was no burn on Narrow Leaf Fig leaves up to concentration of 5 ml* L -1 of essential.