To evaluate the effects of saponins from Chinese Buckeye Seed in the treatment of cerebral edema in patients with stroke or cerebral trauma, a metaanalysis of randomized controlled trials was conducted. Randomized trials that compare the effects of treatment with saponins from Chinese Buckeye Seed to placebo treatment, to lack of treatment, to non-specific treatment, or to mannitol treatment for cerebral edema were identified with electronic and manual searches. No blinding and language limitations were applied. The methodological quality of trials was assessed with the Jadad scale plus allocation concealment. The metaanalysis was performed where data were available. Forty-one randomized controlled trials involving 4066 patients were identified. The methodological quality of the trials was generally low. The combined results showed that intravenous administration of saponins from Chinese Buckeye Seed increased the total effective rate, reduced the mortality and the incidence of renal function impairment in comparison to control treatment. No serious adverse event was reported. Based on the metaanalysis, saponins from Chinese Buckeye Seed can reduce cerebral edema in patients with stroke or cerebral trauma. However, the evidence is not sufficient due to the generally low methodological quality of the studies. Further trials are needed with sufficiently numerous group size and rigorous design.