The menstrual cycle is a vital indicator of a woman’s reproductive health. A typical cycle ranges between 21–35 days and is regulated by the Hypothalamic–Pituitary–Ovarian (HPO) axis. However, several internal and external factors can disrupt this cycle, leading to irregularities such as delayed menstruation. One of the most common causes of menstrual irregularities is stress. Stress is the body's response to emotional, physical, or environmental pressures. It triggers physiological reactions such as increased cortisol production, elevated heart rate, and hormonal imbalance. Stress is one of the most common psychological and physiological challenges faced by university students. Academic pressure, financial constraints, relationship issues, inadequate sleep, and environmental changes can significantly affect students’ health, including their menstrual cycle. Delayed menstruation (also called oligomenorrhea) is a common menstrual disorder characterized by cycles longer than the usual 21–35 days. Stress is the body’s response to any demand or challenge. It triggers the release of stress hormones such as cortisol and adrenaline, which can disturb normal bodily functions. A normal menstrual cycle is regulated by the Hypothalamic–Pituitary–Ovarian (HPO) Axis. Any disturbance in this axis especially hormonal imbalance may lead to delayed menstruation, missed periods and irregular cycles. This study is aim to evaluate the Stress as a Predictor of Menstrual Delay Among Students in Tertiary Institutions In South-South Nigeria. This was a cross-sectional study involving 250 women. A well-structured questionnaire was administered to participants. The study lasted for a period of 2 months. Statistical analysis was done using SPSS version 25.0 and p < 0.05 was significant. The results revealed that 75% of the participants had high academic workload, 64% are facing overcrowding living conditions, 72% are facing financial constraints, 68% are having environmental and security concerns and 86% are facing noise and distractions around campus. These factors increase psychological stress, potentially affecting menstrual health.