Purpose: OnabotulinumtoxinA (BoNT-A) is a promising therapy for treating neurogenic detrusor overactivity (NDO) in individuals with spinal cord injury (SCI). This systematic review and meta-analysis aimed to carry out an in-depth review and to make an objective estimation of the efficacy and safety of BoNT-A on NDO after SCI. Methods: The PubMed, Embase, and Cochrane databases were searched for all relevant articles published from 2001 to 2016 that referred to NDO, SCI, and BoNT-A or botulinum toxin A. All data were recorded in an Excel spreadsheet by 2 individual reviewers. Review Manager version 5.3 was used to carry out the meta-analysis. Results: This analysis included 17 studies involving 1,455 patients. Compared with placebo and baseline, BoNT-A was effective in increasing maximum cystometric capacity, volume at first involuntary detrusor contraction, cystometric bladder capacity (all P<0.00001), compliance (P=0.001), and the number of patients with complete dryness (P=0.0003), and decreasing detrusor pressure, the number of patients with no involuntary detrusor contractions, the maximum flow rate, the incidence of detrusor overactivity (all P<0.00001), and the number of urinary incontinence episodes (P=0.001). There were no statistically significant differences between doses of 200 U and 300 U or between injections into the detrusor and submucosa. There were no life-threatening adverse events. Conclusions: BoNT-A is effective and safe in treating NDO after SCI. There were no statistically significant differences between doses of 200 U and 300 U or between injecting into the detrusor and submucosa. However, more high-quality randomized controlled trials are still needed.