Preparing an extract comprises (a) extracting Ginkgo bilobaleaves with e.g. aqueous acetone; (b) separating major part of the organic solvent from the extract; (c) diluting the remaining concentrated aqueous solution with water; (d) adding ammonium sulfate to the remaining aqueous solution and extracting the formed solution with methylethylketone; (e) concentrating the obtained extract; (f) adding an aqueous solution of a lead salt to the obtained solution; and (g) extracting the remaining aqueous alcoholic solution with an aliphatic or cyclophatic solvent. Preparing an extract of Ginkgo bilobaleaves, comprises (a) extracting Ginkgo bilobaleaves at a temperature of approximately 40-100[deg] C, with aqueous acetone, 1-3C aqueous alcohol or anhydrous methanol; (b) separating major part of the organic solvent from the extract containing up to 10 wt.%, so that the water is added during final stages of distillation; (c) diluting the remaining concentrated aqueous solution with water to obtain a content of solid materials of 5-25 wt.%, allowing to cool by stirring, at a temperature of below25[deg] C, until to form a precipitate, where the resulting precipitate comprises lipophilic components, which does not dissolve well in water, and is separated; (d) adding ammonium sulfate to the remaining aqueous solution and extracting the formed solution with a methylethylketone or a mixture of methylethylketone and acetone; (e) concentrating the obtained extract to a solid material content of 50-70% and diluting the obtained concentrate diluted with water and ethanol to obtain a solution containing 50 wt.% of water and 50 wt.% of ethanol with a content of solid materials of 10 wt.%; (f) adding an aqueous solution of a lead salt to the obtained solution until a change in the brown color to amber color occurs, and separating the formed precipitate, in which a polyamide is used instead of a lead salt; (g) extracting the remaining aqueous alcoholic solution with an aliphatic or cyclophatic solvent with a boiling point of 60-100[deg] C for separating more alkylphenol compounds; (h) concentrating the remaining aqueous alcoholic solution under reduced pressure to a maximum ethanol content of approximately 5%, and adding ammonium sulfate (up to 20 wt.%); (i) extracting the obtained solution with a mixture of methylethylketone and ethanol in a ratio of 8/2 to 5/5, preferably 6/4; (j) concentrating the resulting organic phase to a solid material (50-70 wt.%); (k) adding ethanol (at least 80%) to the obtained concentrate, then cooling at a maximum temperature of 12[deg] C for at least two hours and eliminating the insolubles by filtration and recovering the filtrate; (l) concentrating the filtrate and drying under reduced pressure at a maximum temperature of 60-80[deg] C to obtain a dry extract with a water content of less than 5%, where the process comprises an additional step, which consists to pass an organic phase obtained in one of steps d, i or k, on an adsorbent having a specific surface of greater than 1000 m 2>/g. An independent claim is included for the Ginkgo bilobaextract substantially devoid of persistent organic pollutants, obtained by the process. ACTIVITY : Cardiovascular-Gen.; Nootropic. MECHANISM OF ACTION : None given.