Non-thermal plasma (NTP) is a promising biomedical tool for application to wound healing. However, there is limited scientific evidence that confirms its efficacy to inhibit scar formation. This study aims to investigate the role of non-thermal plasma in scar formation. Two full-thickness dorsal cutaneous wounds of rats were treated with either a non-thermal helium plasma jet or helium. It was determined that the non-thermal plasma jet accelerated the wound healing process from 5 days after surgery (day 5: 41.27% ± 2.351 vs 54.7% ± 5.314, p < 0.05; day 7: 56.05% ± 1.881 vs 75.28% ± 3.914, p < 0.01; day 14: 89.85% ± 2.991 vs 98.07% ± 0.839, p < 0.05). The width of the scars for the NTP group was narrower than those of control group (4.607 ± 0.416 mm vs 3.260 ± 0.333 mm, p < 0.05). In addition, a lower level of TGF-β1, p-Smad2 and p-Smad3 were detected in the NTP treated wounds (p < 0.05, p < 0.01 and p < 0.01). As expected, α-SMA was also significantly decreased in the NTP treatment group (p < 0.01). Moreover, the expression of type I collagen and the proportion of type I to III collagen were lower in the NTP group (p < 0.05). The results of the study suggest that NTP may play a potential role in scar formation by inhibiting the TGF β1 signal pathway and reducing the levels of α-SMA and type I collagen, and may have clinical utility in the future. Scar formation is an inevitable outcome after physical, biological, and chemical injury of the skin, The phenomenon is characterized by excessive deposition and irregular distribution of extracellular matrices (ECM), in addition to an overproduction of fibroblasts 1-3. Patients with severe scars caused by burns, scalds or serious traumas, experience physical and mental anguish that is typically associated with the dysfunction and disfigurement caused by tissue hypertrophy or severe contraction 4. Therefore, even incremental improvements in scar management could result in significant benefits to patients. To date, numerous therapeutic approaches have been developed for the treatment of scars including surgical excision, corticosteroid injection, and laser therapy 5,6. However, in many cases these treatments do not result in satisfactory outcomes. The treatment of scars is still a formidable task, and advanced treatments or techniques for the minimization of scarring are needed. Plasma medicine, a rapidly developing interdisciplinary field, has already developed as a new innovative approach for biomedical and clinical applications 7. Emerging evidence suggests that non-thermal plasma (NTP) is potentially beneficial for bacteria disinfection, blood coagulation, and cancer therapy 8-12. NTP has also been shown to play a role in wound healing 13. However, there are limited experimental studies on the application of NTP to inhibit scar formation. In this study, we aimed to investigate the efficacy of non-thermal plasma in the inhibition of scar formation in a rat model. Based on histological observation and immunohistochemistry quantitative analysis, we concluded that plasma e...