INTRODUCTION:
Premenstrual Syndrome (PMS) is a prevalent but under-addressed menstrual health issue affecting the quality of life (QoL) of adolescent girls. Despite its impact on school attendance, mental health, and social participation, limited data exist on PMS in Nigerian adolescents. This study assessed the knowledge, prevalence, and associated QoL outcomes of PMS among female adolescents in public secondary schools in Ibadan Metropolis, Oyo State.

METHODS:
A school-based cross-sectional study was conducted among 357 female adolescents aged 10–19 years between September 2023 and March 2024. A multistage sampling technique was employed. Data were collected using a pretested, interviewer-administered questionnaire. Knowledge scores (maximum = 17) and QoL scores (maximum = 24) were categorized using mean thresholds (Mean±SD). Chi-square test and binary logistic regression were used to assess associations and predictors of QoL. A 5% level of significance was adopted.

RESULTS:
The mean age of respondents was 14.78±1.45 years; mean age at menarche was 12.96±1.24 years. The prevalence of PMS was 76.5%. Common severe symptoms included tiredness (17.6%), acne (16.5%), abdominal pain (15.8%), and mood swings (15.8%). Over half of the respondents (52.9%) had poor knowledge of PMS. Approximately 45.4% of adolescents reported a poor quality of life due to PMS. Factors associated with lower odds of good quality of life included early menarche (age 10–13 years; AOR=1.883, 95% CI: 1.044–3.397) and severe backache (AOR=0.292, 95% CI: 0.090–0.943; p<0.05).

CONCLUSIONS:
Premenstrual syndrome is highly prevalent among adolescent girls and is associated with reduced quality of life. The study highlights a high burden of PMS and its impact on adolescent well-being. There is a critical need for comprehensive menstrual health education, psychosocial support, and targeted school-based interventions to mitigate the negative effects of PMS and improve QoL among adolescent girls.