Thymol is one of the most important phytochemical components because of its pharmacological and bioactive potential effects. This review focuses particularly on thymol as an alternative natural antiparasitic with potential use in the pharmaceutical industry. This is in line with the preferences of the natural products for treatment being safer and without side effects. The biosynthesis pathways of thymol and carvacrol have been discussed, and mechanism of action of thymol on parasites. Studies on thymol confirmed the activity of thymol as anti-parasite against anthelmintic, <em>Trypanosoma</em> ssp., <em>Toxoplasma gondii</em>, <em>Leishmania</em> spp., <em>Plasmodium falciparum</em>, <em>Giardia duodenalis</em>, <em>Eimeria</em> ssp., <em>Cryptosporidium baileyi </em>and<em> Cryptosporidium galli</em>.