Abstract: The objective of this investigation is to document ethnoecological knowledge through a survey on diuretic plant species used by the inhabitants of the North Western Mediterranean region of Egypt (from Burg El-Arab to Salum) for use in treatment of urinary system problems. The study revealed that the number of plant species used by the bedouins was low (35 species) and some species such as Alhagi maurorum , Polygonum equisitiforme, Sylibum marianum etc. recorded in the ancient Arabic medicine were not being used in the surveyed area. This may be due to the absence of the experiences and awareness of the inhabitants beside the rareness of these species which resulted from the extensive land use in the last decades. The herbal formula are simple and complex formula were rarely used. The herb may be decoct to be taken orally or applied locally in the form of fomentation. In the North part (coastal strip) of the surveyed area the kidney herbal remedies have decreased in importance and old knowledge begin to diminish, probably due to the shifting from folk to biomedical therapies. Wood cutting, overgrazing, intensive agriculture, obliteration of limestone ridges and building summer resorts are the main factors of habitat and species degradation.