Objective To determine the clinical efficacy of posterior fossa decompression with cisterna magna reconstruction for the treatment of Chiari malformation I associated with syringomyelia.Methods The clinical data of 22 patients with Chiari malformation I associated with syringomyelia were retrospectively analyzed.Results Symptoms resolved or improved in 19 patients within one week after surgery. Fourteen patents reported resolution or improvement of symptoms when followed up for six months to two years postoperatively. Syringomyelia was alleviated or resolved in 10 patients.Conclusions Posterior fossa decompression with cisterna magna reconstruction is a safe and effective treatment strategy for Chiari malformation I associated with syringomyelia.