This study aimed to evaluate the toxicity of foliar extracts of four medical plants, harmal (Peganum harmala L.), laurel (Laurus nobilis L.), marmaria (Salvia officinalis L) and zizyphus (Zizyphus spina-christi. Willd) on fruit fly Ceratitis capitata (Wiedemann)and peach fly Bactrocera   zonata (Saunders).The effect of these extracts on larvae pupal duration, percent of malformation, percent of reduction in infestation and percent reduction innumber of punctures /fruit .The results proved that, harmal, laurel and zizyphus show toxic effect on both C. capitata and B. zonata larvae. harmal was more toxic to the larvae of  both flies  than the other three compounds ,with LC₅₀ values 8.52 and10.5 ml/L for both flies,respectively. Harmal recorded  the highest mean of malformation  percent 48.79 and 43.62% for C. capitata and  B. zonata, respectively followed by  laurel and zizyphus in case of C. capitata and  zizyphus and laurel in case of B. zonata. Harmal recorded the highest mean of reduction percent of infestation followed by laurel and marmaria in case of C. capitata and laurel and zizyphus in case of B. zonata. the highest mean of percent reduction in number of punctures/fruit was recorded after treatment  with harmal and laurel for both C. capitata  and B. zonata.  The tested extracts show toxic effect on larvae of both flies, cause changes in some biological measurements and reduce both percent of infestation and number of punctures/fruit, so these extracts could be incorporated in management programmes of both fruit flies.