Caffeine, is a bitter and crystallized alkaloid and a family member of methylxanthine. Caffeine is inherently antiinflammatory and there is in the different food sources such as coffee, tea, cola, chocolate, some types of cakes, biscuits and soft drink. It is a factor that affects the premenstrual syndrome (PMS) disorder. Due to the fact that there still exists uncertainty on the effects of caffeine on PMS, it was decided to conduct a study to evaluate the effect of caffeine on premenstrual syndrome. This study is an analytical-descriptive study which has been conducted on the 173 Medical Sciences students of Zahedan University in 2015. PSST standard questionnaire was used to collect information in which the reliability and validity were measured in Iran. Finally, after data collection, data have been analyzed by using SPSS 19software, descriptive statistics and test, chi-square, Fisher's exact test and ANOVA. The mean age of participants was 21.37 ± 2.59 in the study and 93 individuals (53.8%) of them used caffeine in this study. There was no significant relationship between the age and marital status and dysmenorrhea, duration of bleeding and PMS (P> 0.05). The relationship between the use of caffeine with PMS was significant (P <0.05) results showed that the relationship between the use of caffeine associated with depression was significant (P <0.05) and those ones with depression were used less caffeine. In this study, caffeine has effect on the menstrual syndrome and people who use caffeine were less affected by the Bund of PMS. Of course, in order to obtain reliable results, there is a need for an accurate tool for measuring caffeine.
