Aims: to establish normal reference ranges, for maximum and average urine flow rates in Hungarian children ol both sexes and different body surface areas, to look lor new parameters to detect early signs of outflow obstruction, to investigate micturition in children with type 'l diabetes, and to look for early signs of diabetic autonomic neuropathy, as well as to investigate the neurotoxic effect of vincristine therapy on bladder function, to identify and quantify the etiologic lactors that contribute to voiding dysfunction. Methods: After spontaneous micturition subjects drank 15 ml/kg ol water. They voided at first desire to void and the next micturition was al maximal sensation of bladder fullness. All micturitions were into a flowmeter. Videourodynamics consists of cystomanometry, which is the measurement of detrusor pressure, detrusor activity, sensation, capacity, and compliance, during controlled bladderlilling and subsequent voiding, which was combined with conventional voiding cystourethrography using X-ray contrast material. Results: 5672 children (aged 0-18 years) underwent urodynamic examination between 1986 and 2022.53514110 children (aged 3-18 years) participated in a prospective study. 200 ol them were healthy, 282 boys had hypospadias, 37 has diabetes mellitus, and 16 undergoing vincristine therapy because of oncological problems. 517 children (aged 5 days to 20 years) prospectively underwent videourodynamics. 615 children had urinary incontinence. 542 had urge incontinence and uroflow showed a sharp-peaked flow curve with thickened bladder wall and increased detrusor muscle acceleration. 451/1305 children with nocturnal enuresis had non-monosymptomatic enuresis with urge incontinence. 105 children had dysfunctional voiding. Gonclusions: The advent ol modern urodynamic and neurophysiologicaltechniques has allowed a better insight into the complex function or dysfunction ol the lower urinary tract. Urodynamics is essential to clarify the pathomechanism of various urinary disorders and thereby opening the way lor targeted treatment.  Kulcsszavak: urodynamics; uroflowmetry; urine flow acceleration; normative reference values; paediatrics; children