Abstract: Background and Objective: Disorders in the menstrual cycle are a significant gynecological problem among female adults and a source of anxiety to them and their families. In Saudi Arabia, the most prevalent cause for college absenteeism is severe menstrual pain and menstrual irregularity. This study was conducted to assess the relationship between menstrual problems and body mass index among undergraduate female university students, Saudi Arabia. A cross-sectional design adopted in this study. Materials and Methods: The research conducted in three female colleges at Wadi Alddawasir Province, which affiliated to Prince Sattam Bin Abdulaziz University, Saudi Arabia. A purposive sample utilized. Results: The total sample was 3213 undergraduate single female students in the academic year 2016-2017, the data collected through the interviewing assessment sheet. The present study results revealed that out of 3213 students’ girls, 53.9% of the students belonged to normal weight distribution, 21.8% were overweight, 12.8% were obese and 11.5% were underweight. A statistically significant relationship observed between BMI and duration of menses, average numbers of pads used daily during menses dysmenorrhea, menorrhagia and polymenorrhea. Conclusion: A positive correlation between body mass index and menstrual characteristics related to the duration of menstruation and the amount of blood flow also dysmenorrhea, menorrhagia and polymenorrhea. So, the finding in the present study indicated the health education program related to the menstrual cycle is needed for undergraduate female students.