In the rehabilitation of severely brain-injured patients, solving urinary incontinence poses a therapeutic challenge. From this study it appears that incontinence does not always result from impaired neuropsychological functioning. If habituation procedures fail, an underlying organic cause (usually detrusor hyperactivity with synergic sphincter action) for persistent urinary incontinence can be demonstrated in a large number of patients. In patients with a severe pelvic fracture a pudendal nerve lesion must be ruled out.