Sexually transmitted infections (STIs) are infections that spread mainly through sexual contact with an infected individual. They are major health problems affecting mostly young people and major cause of morbidity and mortality worldwide, not only in developing countries. Infections of the genitourinary or reproductive tracts are major problems of women's sexual health. They are commonly found in women of reproductive age and usually start with vaginal discharge. This study was aimed at assessing the prevalence of sexually transmitted infections among selected adolescent females attending a tertiary institution in the Omu-Aran community. A total of one-hundred (100) consenting individuals aged 10-25 years were recruited for the study. A well-structured questionnaire was distributed to all participants to obtain their data and demographic information. High vaginal swab samples were collected from consenting participants using sterile swab sticks. The swab sticks were cultured on four different culture media: Chocolate Agar, Blood Agar and MacConkey Agar for significant bacterial growth and Sabouraud dextrose Agar for significant fungal growth. Findings from the microscopy assay showed pus cells, epithelial cells, bacterial cells and yeast cells, of which yeast cells were found in 33% of samples screened, while the main organisms isolated include Candida sp. (33%), Enterobacteria (20%), and Staphylococcus sp. (1%). From the result obtained, a prompt enlightenment campaign and the need for periodic checks among females are highly advocated to reduce or outrightly eliminate the spread of infections among the population.