Objective To conduct a systematic review of the efficacy and safety of posterior fossa decompression (PFD) and posterior fossa decompression plus duraplasty (PFDD) in patients with Chiari malformation type I with syringomyelia.Methods Articles published up to 2019 were collected from databases such as Embase, Cochrane, PubMed, Ovid, Medline, ScienceDirect, Google Scholar, Wanfang Data, and CNKI; the articles were screened for randomized controlled or non-randomized controlled studies which were conducted to compare PFD and PFDD. Postoperative clinical symptoms, radiological improvements, and complications were summarized, and data analysis was performed using Revman (version 5.3).Results A total of 10 articles were included in the study, including 3188 cases, which consisted of 1383 cases in the PFDD group and 1805 cases in the PFD group. Compared with the PFD group, the PFDD group had significantly higher rate of improvement in syringomyelia (odds ratio[OR]:5.53, 95% confidence interval[CI]:2.86-10.69), symptom remission rate (OR:2.53, 95% CI:1.30-4.91), complication rate (OR:3.46, 95% CI:1.40-8.59), cerebrospinal fluid leak incidence rate (OR:9.36, 95% CI:2.63-33.34), and pseudomeningocele rate (OR:1.89, 95% CI:1.28-2.79) (all P<0.05). There were no significant differences between the two surgical approaches in the incidence rates of incision infection (OR:1.44, 95% CI:0.57-3.59) and subcutaneous hydrops (OR:1.71, 95% CI:0.50-5.80) (P>0.05).Conclusions PFDD is more effective than PFD in patients with Chiari malformation type I with syringomyelia.