The article presents data on the establishment of the effectiveness of intrauterine administration of the experimental herbal preparation Fit-O-Metrin based on extracts of thyme, oregano and barberry in postpartum endometritis in sows. Inflammation of the mucous membrane of the uterus is a fairly common disease of the genitals in sows, especially after farrowing, which often occurs against the background of viral infection due to bacterial or parasitic contamination of the uterus, as well as due to violation of veterinary rules of pigs and feeding poor quality feed, fungus and their toxins. In most cases, endometritis in sows secretes bacterial microflora and is treated with drugs to which the microflora is not resistant or use new broad-spectrum antibiotics, but it is known that they act not only on its microflora but also saprophytes of the vagina and its dorsum, turn may be the etiological factor of settlement in these organs of antibiotic-resistant bacteria. Treatment of 20 sows of the control group was carried out according to the protocol adopted in the farm: Cobactan at a dose of 4 ml per 100 kg intramuscularly, once a day for 3 days, Dexafort at a dose of 1 ml per 50 kg, intramuscularly, once, Introvit in dose of 10.0 ml per animal, intramuscularly once, Catozal at a dose of 10.0 ml per animal, intramuscularly once, Galapan at a dose of 2.0 ml per animal intramuscularly, once. 10 animals of the experimental group to this protocol in the uterus was injected Fit-O-Metrin drug at a dose of 30.0 ml once. During the studies, the duration of exudate secretion after the end of treatment was taken into account and a sonographic examination of the uterus was performed, in addition, the nature of uterine secretions before insemination was taken into account. 30-35 days after insemination with the help of a sonographic device examined the condition of the uterus of sows to diagnose pregnancy or infertility. The prevalence of postpartum catarrhal-purulent and purulent endometritis among sows after farrowing was 25.0 %, purulent exudate was excreted in 30 % of sick animals, in the rest (70 %) purulent-catarrhal exudate flowed from the vagina. After using Fit-O-Metrin drug for postpartum endometritis in sows, the number of animals admitted to insemination increased by 55.0 % (p≤0.001), and their fertility by 34.4 % (p≤0.05).