BACKGROUND Guizhi Fuling Wan (GFW) is one of the most widely known traditional Chinese medicine (TCM) formulations that has long been used in China for the treatment of primary dysmenorrhea (PD). However, the quality of evidence is limited and there are few studies on specific TCM syndromes of GFW for PD. OBJECTIVE To evaluate the efficacy and safety of GFW on PD patients with the heat-burning blood-stasis syndrome. METHODS This was a randomized, double-blinded, placebo-controlled trial. Eligible patients were recruited and randomly assigned to one of two groups to receive GFW or the placebo twice daily for three menstrual cycles with a 3-month follow-up. The primary outcome was the baseline-to-month 6 change in pain intensity measured by a Visual Analog Scale (VAS). The secondary outcomes included the changes in the Cox Menstrual Symptom Scale (CMSS), the Self-rating Anxiety Scale (SAS), the Self-rating Depression Scale (SDS), and the TCM syndrome scale from baseline to month 6. Additionally, adverse effect was assessed. RESULTS A total of 353 patients were screened for eligibility and 128 were randomly assigned, of whom 121 completed all treatments and follow-ups. In both the full analysis (FAS) and the per-protocol analysis (PPS), the VAS score of pain intensity decreased significantly more in the GFW group than in the placebo group from baseline to month 6 (P < 0.01). Similarly, the decrease in CMSS, SAS and TCM syndrome scores was greater in the GFW group compared with the placebo group (P < 0.01). There were no differences in SDS scores between the two groups (P > 0.05). In addition, no serious adverse events were observed. CONCLUSIONS Our findings revealed that GFW significantly alleviated the severity of menstrual pain in PD patients with the heat-burning blood-stasis syndrome without significant adverse effects.