BACKGROUND: A number of clinical trials addressing olfactory ensheathing cells for the treatment of chronic spinal cord injury have been conducted in the world, but the efficacy and safety are still controversial. OBJECTIVE: To evaluate the safety and efficacy of olfactory ensheathing cell transplantation for chronic spinal cord injury, and to further compare its short-and long-term efficacy. METHODS: PubMed, Cochrane Library, EMBASE, CNKI and WanFang databases were searched at July 23, 2018 for retrieval of clinical trials addressing olfactory ensheathing cells in the treatment of chronic spinal cord injury. Types and cases of adverse events during the safety trial should be recorded in detail. In the enrolled studies, American Spinal Injury Association scale was used to assess the motor, light touch, and pinprick scores of spinal cord injury patients before and after cell transplantation. The follow-up time was recorded. Systematic evaluation of efficacy data was performed using Review Manager 5.3. RESULTS AND CONCLUSION: Both short-and long-term follow-up data showed that the neurological function of patients was significantly improved after olfactory ensheathing cell transplantation (P < 0.05) , and the results were homogeneous (I2 < 50％ and P> 0.1). However, the long-term efficacy was not as good as the short-term efficacy, which may be related to chronic rejection and olfactory ensheathing cell survival. The overall adverse event rate was 8.99％, and no complications associated with olfactory ensheathing cells occurred. These findings show that olfactory ensheathing cell transplantation is effective and safe in the treatment of chronic spinal cord injury, but it is still necessary to explore more minimally invasive approaches to reduce surgical complications. In addition, a large number of high-quality experiments and clinical trials are warranted to confirm factors affecting the long-term efficacy of olfactory ensheathing cell transplantation.