The venom of animals, including snakes, scorpions, and spiders is a complex combination of proteins, peptides, and other biomolecules as well as some minerals. Among the biomolecules of some animal’s venom, small peptides that lack disulfide bands known as Non-Disulfide Bridge Peptides (NDBPs) potentiate the bradykinin by preventing the conversion of angiotensin ۱ to angiotensin ۲ using the mechanism of inhibiting the Angiotensin-Converting Enzyme activity and finally reducing the blood pressure in the victims. This feature of the NDBPs of animal’s venom is suggested as the potential of biological drugs. This study aimed to isolate venom components of three species of Iranian medically important scorpions and study the bradykinin potentiating effect of them. The scorpion specimens were collected from the venomous animals and antivenom production department of Razi Vaccine and Serum Research Institute, Karaj, Iran. Moreover, venom extraction was performed by electrical shock (۵ volts). The obtained liquid venom of three species specimens was frozen and lyophilized immediately and then preserved in a cool and dried place. The isolation of the venom components for each scorpion was carried out using high-performance liquid chromatography. The obtained ranges of venom fractions (zones) were tested on isolated tissues of guinea-pig ileum and rat uterus using organ bath instrumentation in several replicates. The bioassays resulted in the peptides, including Z۱ and Z۲ regions in the venom fractionsof the Hottentotta saulcyi, Z۲ in Odontobuthus doriae, as well as Z۲ and Z۳ in Mesobuthus eupeus demonstrated bradykinin potentiating effect. It is concluded that Bradykinin Potentiating Factors were traceable in the venom of all three scorpion species. Therefore, these venoms have the therapeutic potential to exploit biological-based drugs.