Background: The incidence and severity of primary dysmenorrhea are influenced by various factors. The aim of the present study was to review nutritional factors influencing primary dysmenorrhea. Methods: Academic databases including Web of Science, EMBASE, Scopus, and PubMed (including Medline) were searched using keywords of nutrition, diet, and primary dysmenorrhea. In this study, observational studies that were published in English from 1990 to April 2018, which focused on nutritional factors affecting primary dysmenorrhea, were selected. The evaluation of studies was performed using a modified STROBE checklist with 10 items. Results: Out of 5,814 retrieved studies, 38 articles met inclusion criteria and were included for final data synthesis. The increased consumption of fruits and vegetables as the sources of vitamins and minerals, as well as fish and milk and dairy products have positive associations with less menstrual pain. Inconsistent results were reported on the consumption of other nutritional groups. Studies showed negative associations of meal skipping and following diet to lose weight with severity of dysmenorrhea. Conclusion: A few studies showed inconclusive findings due to methodological heterogeneities for assessing nutritional habits and different methods of measuring dysmenorrhea pain. Therefore, further analysis and future interventional studies with stronger methodologies are required.