Objective: Investigation of the diagnostic value of natural fill cystometry(NFC) in children with neurogenic bladder in comparison to conventional videocystometry (CVC). Methods: We investigated 20 children (aged 6-11;15 girls and 5 boys) with the following diagnoses: 6 myelomeningocele, 2 tethered cord syndrome, 1 syringomyelia, 1 Vater syndrome, 1 suprasacral spinal cord injury, 9 suspected neurogenic bladder. We carried out a NFC after completing standard diagnostics including a slow-filling CVC. Results:All investigations were completed successfully. The investigation lasted 6-20.5 h (mean 11:15 h). We registered phases of sleep, waking consciousness and micturition. CVC findings were confirmed in 45%: normal bladder function was confirmed in 2 patients (10%), bladder hyperactivity was confirmed in 7 patients (35%). In 55% we obtained different findings on NFC in comparison to the slow-filling CVC: bladder hyperactivity was not confirmed in 2(10%), detection of bladder hyperactivity was found in 4 children (20%) with normal bladder function on CVC, detection of bladder hyperactivity on NFC was found in 5 children (25%) with low-compliance bladder on CVC. In 45%of all children, NFC detected new findings compared with CVC diagnoses. In 10%, possible artifacts (e.g. due to catheterization) of CVC were recognized. CVC findings were confirmed in 45%. Conclusion: These results are preliminary but they suggest that this is a new diagnostic method for improving the diagnostic standard in the childhood neurogenic bladder.