Bacterial vaginosis is one of the most common vaginal infections, occurring in about 70% of women of reproductive age. It is important to note that bacterial vaginosis is not a sexually transmitted disease, but its presence significantly increases the risk of developing one. The state of her vaginal microflora is of primary importance for the reproductive health of every woman – in bacterial vaginosis, there is an imbalance between the beneficial Gram-positive lactobacilli and Gram-negative anaerobic microorganisms, which are usually a normal part of the vaginal flora. The vaginal microflora is represented by Gram-positive microorganisms, among which are Döderlein’s lactobacilli, and Gram-negative ones, and under normal conditions, lactic acid bacteria prevail over Gram-negative anaerobes and are in a ratio of 2-5:1. These microorganisms maintain an acidic environment in the vagina with a pH of 3.5-4.2 by producing lactic acid, which has a local protective effect. In pathological conditions, the balance is disturbed, excessive development of pathogenic anaerobes is observed, the environment in the vagina becomes alkaline and bacterial vaginosis develops. From an etiological point of view, bacterial vaginosis is a polymicrobial infection, but the main causative agent is anaerobes of the Gardnerella vaginalis species. Bacterial vaginosis is not a sexually transmitted infection, but it increases the risk of contracting one. Early sexual contact, multiple sexual partners, use of vaginal douches, intimate cosmetics containing perfume substances, use of intrauterine devices are considered risk factors for the development of the condition. How can we recognize if we suffer from bacterial vaginosis? One of the main symptoms of bacterial vaginosis is a change in the nature of the vaginal discharge. Its amount increases, its color changes to gray, gray-whitish, yellowish, an unpleasant fishy smell appears. These symptoms may be accompanied by symptoms typical of vulvo-vaginal infections such as vaginal redness, swelling, itching, burning during urination (dysuria), pain during intercourse (dyspareunia). The diagnosis of bacterial vaginosis can usually be made on the basis of the clinical picture and the results of the vaginal discharge taken during a gynecological examination. There are so-called Amsel’s criteria, according to which three of the following four criteria are needed to make the diagnosis: 1. Appearance of vaginal discharge with a grayish color and an unpleasant fishy smell; 2. Detection of pathogenic microorganisms under a microscope; 3. Establishing an alkaline environment in the vagina – pH above 4.5; 4. Appearance of a fishy smell when 10% potassium base is added to the secretion taken from the vagina. The occurrence of bacterial vaginosis during pregnancy carries the risk of miscarriage or premature birth, which is why timely diagnosis and treatment are essential.Treatment of the condition due to its anaerobic nature consists of administration of metronidazole – orally and/or in combination with vaginal globules or clindamycin – orally or in the form of a vaginal cream. The mentioned medications are safe during pregnancy, but it is recommended to use them after the end of the first trimester. Because bacterial vaginosis is not a sexually transmitted disease, concomitant treatment of the sexual partner is not required. What is important to know and do about the prevention of bacterial vaginosis? Of primary importance is limiting the number of sexual partners and sexual contacts at an early age. It is mandatory to use protective means (condoms) during sexual intercourse. Vaginal douching is an unhealthy practice that disrupts the natural vaginal microbiota and increases the risk of infections. The products used for intimate hygiene are also important – it is recommended to use those that do not contain additional perfume substances. It is also recommended to wear cotton, breathable underwear and use hypoallergenic laundry detergents. Bacterial vaginosis is a state of disturbed balance of the vaginal microflora, which manifests itself with characteristic symptoms. Its treatment is complex and, apart from the administration of antibiotics, following preventive measures is essential to limit recurrent infections.