This study examined the relationships between personality traits, premenstrual syndrome, body perception, and eating behaviours among university students. This study was conducted with cross-sectional, descriptive, and correlational design. Data from 737 university students in Turkiye were analysed using structural equation modelling. The participants filled out the Premenstrual Syndrome Scale, the Quick Big Five Personality Test, the Body Perception Scale, and the Dutch Eating Behaviour Questionnaire and gave their information about their socio-demographic characteristics. A structural equation model with an excellent fit (CMIN/DF (9.561/5) = 1.912, GFI = 0.997, CFI = 0.996, and RMSEA = 0.035) showed that body perception and premenstrual syndrome (PMS) played a mediating role in the correlation between personality traits and eating behaviours. Personality traits were also correlated with body perception, PMS, and eating behaviours. The complex interaction between these factors suggests that interventions to promote healthy eating behaviours should address the multifaceted nature of such correlations. Strategies and interventions should be planned by assessing the interaction of personality traits, PMS, and body perception with each other to control the negative eating behaviours of university students.