Objectives: Dysmenorrhea is one of several gynecological issues that occur among women of reproductive age. In addition, it appears as pain that forms in the pelvis or lower abdomen and spreads to the back and thighs. The peripheral blood among women with dysmenorrhea increases the synthesis and the concentration of oxytocin, F2α prostaglandin hormone, vasopressin, interleukin-6 (IL-6), and tumor necrosis factor-α (TNFα ). In this regard, this study aimed to determine the effect of slow-stroke back massage (SSBM) on the levels of β-endorphins, IL-6, TNF-α , and menstrual pain intensity (MPI). Materials and Methods: Based on the aim of the study, the posttest only quasi-experimental method with the control group design approach, pretest-posttest control group approach, and purposive sampling techniques were applied for sample selection. The samples were divided into SSBM and control groups each containing 20 subjects. The numeric rating scale (NRS), β-endorphin, IL-6, and TNFα levels were measured using the indirect enzyme-linked immunosorbent assay. Then, data were analyzed by paired sample t test and independent-samples t test with α ≤ 0. 05. Results: The results revealed that SSBM had an effect on the intensity of menstrual pain (P < 0. 05), and differences were found between β-endorphin levels, IL-6, TNFα , and MPI among SSBM and control (P < 0. 05) groups. Accordingly, SSBM can stimulate releasing β-endorphin levels and reducing pro-inflammatory cytokines (IL-6 and TNFα ). Conclusions: In general, SSBM is a nonpharmacological action that is effective in primary dysmenorrhea.