Study design: Cross-sectional study. Objectives: To study the prevalence of incontinence, problem perception and determinants of urinary and faecal incontinence in young adults with spina bifida. Setting: Nation-wide study in the Netherlands. Participants: A total of 179 of 350 invited patients participated, including 37 patients with spina bifida occulta and 142 with spina bifida aperta, of whom 119 had hydrocephalus; 41% were male and mean age was 20.4 (range 16-25 years). Methods: Data were collected from interviews, physical examination, neuropsychological tests and medical records. Results: Urinary and faecal incontinence was common in young adults with spina bifida (60.9 and 34.1%, respectively), regardless of the bladder and bowel management they used. The majority of urinary and faecal incontinent patients perceived this as a problem (69.7 and 77.0%, respectively). Spina bifida aperta, hydrocephalus and a level of lesion of L5 or above were associated with patients suffering from urinary and/or faecal incontinence. Predictors of perceiving urinary incontinence as a problem were, in addition to being incontinent, not having hydrocephalus and having a level of lesion of L5 or above. The only predictor of perceiving faecal incontinence as a problem was the frequency of incontinence. Conclusion: A majority of young adults with spina bifida suffer from urinary and faecal incontinence and most of them perceive their incontinence as a problem. Therefore, further efforts are important to improve urinary and faecal continence.