Polygonum cognatum Meissn. (Polygonaceae) is a wild edible plant known locally as "solucanotu, madimak" in Turkey and it has been used for various purposes, such as diuretic and antidiabetic, as well to treat oxyuris and worms internally in humans. The present study was carried out to investigate the anthelmintic activity of various extracts were obtained from the aerial parts of P. cognatum in order to justify its traditional usage in Turkish folk medicine. n-Hexane, ethyl acetate and methanol extracts were prepared from the aerial parts of the plant, successively. The anthelmintic potentials of these extracts were evaluated on mice naturally infected with Syphacia obvelata and Aspiculuris tetraptera. Cellophane perianal tape test and fecal flotation test were used for the activity screening. The results were compared with control and reference groups. In addition to all these experiments, the total amount of phenolic compounds and tannin contents thought to be responsible for the activity were evaluated for all extracts. According to the results, it has been found that the methanolic extract reduced the number of S. obvelata (66.8%) and A. tetraptera (73.4%) eggs. Moreover, the methanolic extract include higher amount of total phenolic compound (48.75 +/- 0.82 mg of GA/g of extract) and tannin (30.04 +/- 0.22 mg TA/g of extract) than n-Hexane (17.21 +/- 0.75 mg of GA/g of extract; 6.82 +/- 0.41 mg TA/g of extract) and ethyl acetate (25.06 +/- 0.94 mg of GA/g of extract; 10.29 +/- 0.34 mg TA/g of extract); therefore the anthelmintic activity could be related to these constituents. The present study explored the anthelmintic potential of P. cognatum. Further studies should be conducted into the mechanism of these compounds' against helminths. This study can be an important step in the discovery of new anthelmintic agents.