Introduction Vaginal discharge (VD) is a common condition that affects women during their childbearing years and often requires medical attention. It results from the physiological secretion of cervical and Bartholin's glands, as well as the shedding of vaginal epithelial cells caused by bacterial action in the vagina, which alters the acidic environment of the vagina.Experiencing vaginal symptoms is a common reason for seeking medical attention, especially among women during their reproductive years. This often leads to a visit to an obstetrician or a gynecologist. Accordingly,addressing such issues becomes even more crucial. The aim of this study is to assess the knowledge and practice regarding abnormal VD (AVD) among adolescent females in Riyadh City, Saudi Arabia. Methods The present study utilized a correlational cross-sectional survey methodology conducted in Riyadh City. The questionnaire was employed as thedata collection instrument from November 2022 to November 2023. Eligibility for inclusion was limited to adolescent femalesand students living in Riyadh City, aged from 14 to 20 years. Electronic consent was obtained from participants aged 18 years and above, while consent from guardians was sought for those below 18 years. This sample size was determined with a minimum requirement of 500 participants, and 824 were involved. The questionnaire encompassed several sections, including demographic characteristics (gender, age, education, and menstruation history), history of AVD, knowledge regarding VD, and students' practices and behaviors related to VD. Cronbach's alpha values for all the sections were more than 0.7. Data analysis was performed using statistical software, employing descriptive analysis, chi-square tests, and t-tests. Results A total of 824 girls were included, and their ages ranged from 14 to 20 years, with a mean age of (16 years ± 5) years old. Exactly 697 (84.6%) were high school students. Most of the study students (85.1%; 701) complained of an AVD at any point in their lives. Only 97 (11.8%) of the study students had a good knowledge level of VD. Higher age, marriage, late menarche, and seeking medical care for complaints of VD were the factors associated with a high knowledge level about VD (P<0.05). Additionally, 44.2% of school-age females sought medical care when experiencing AVD, with reasons including worsening symptoms over time and fear of serious diseases. However, a significant portion of participants opted for self-treatment using herbal remedies, medication from pharmacies, or leaving VD untreated, citing reasons such as perceiving it as a simple condition or fearing examination and disclosure. Conclusion In summary, the current study revealed that adolescent femalesdemonstrate a sub-optimal level of knowledge regarding AVD. These findings are primarily observed among adolescent girls and individuals who exhibit a reluctance to seek appropriate medical intervention when having AVD.