Primary dysmenorrhea (PD) is a leading cause of dysmenorrhea among adolescent girls. Manual acupuncture may be considered as an effective treatment for PD, but high-quality evidence remains limited. This trial aims to evaluate the efficacy and safety of acupuncture for the prevention of PD as compared with sham acupuncture and usual care. This is a three-arm, randomized, controlled clinical trial in which the patients, assessors, and statisticians will be blinded. A total of 300 acupuncture-naive patients who were diagnosed as PD will be randomly allocated to the verum acupuncture, sham acupuncture, or usual care groups in a 2:2:1 ratio. Patients in the verum acupuncture group will receive manual acupuncture at specific acupuncture points with penetrating needling, while those in the sham acupuncture group will receive non-penetrating needling at non-acupuncture points. They will be given five sessions over a menstrual cycle for 3 menstrual cycles. Patients in the usual care group will receive health education and informed to receive manual acupuncture for free after waiting for 7 menstrual cycles. The primary outcome will be the change from baseline in the Cox Menstrual Symptom Scale Score (CMSS). The secondary outcomes will be the changes in Massachusetts General Hospital Acupuncture Sensation Scale (MASS), visual analog scale (VAS), Short-Form McGill Pain Questionnaire 2 (SF-MPQ-2), Pittsburgh Sleep Quality Index (PSQI), Beck Anxiety Inventory (BAI), Beck Depression Inventory II (BDI- II), Acupuncture Expectancy Scale (AES), 60-item NEO Personality Inventory-Short Form (NEO-FFI), and acute medication intake. The adverse events will be recorded at every visit. The analyses will be performed base on a full analysis set (FAS) and a per-protocol set (PPS). This study may provide high-quality evidence regarding the efficacy and safety of manual acupuncture for PD. In addition, the results of this study will help to identify the efficacy of acupuncture due to the specific effects of acupuncture or placebo effects of acupuncture ritual. Clinical Trials.gov NCT02783534 . Registered on 26 May 2016.