STUDY DESIGN:This was a multicentre, prospective, randomised study. OBJECTIVES:To compare the outcomes of intradetrusor and suburothelial onabotulinumtoxinA injections in patients with spinal cord injury and refractory neurogenic detrusor overactivity (NDO). SETTING:Urology departments of two tertiary hospitals in the Czech Republic. METHODS:A total of 32 spinal cord injury patients with severe NDO refractory to the standard anticholinergic treatment were randomised to receive either intradetrusor or suburothelial 300 IU onabotulinumtoxinA injections. Subjective satisfaction, bladder diary data and urodynamic data were compared in both groups before treatment and at 3 months post treatment. RESULTS:In all, 64.3% patients in the intradetrusor group and 88.8% patients in the suburothelial group were subjectively satisfied with the treatment. There was a significant post-treatment improvement in both groups regarding the number of catheterisations over 24 h, number of incontinence episodes over 24 h, catheterised volume, cystometric capacity, volume at first involuntary detrusor contraction, maximal detrusor pressure during filling and detrusor compliance. No significant differences between the groups were observed, with the exception of improvement of detrusor compliance, which was better in the intradetrusor group. There was one adverse effect comprising transient muscle weakness that was reported by one patient in the intradetrusor group. CONCLUSION:Results in both groups were comparable. The authors favour suburothelial onabotulinumtoxinA injection because this method allows more precise toxin localisation.