The reason for our search was various investigations about urinary tract dysfunctions in enuretic children. OBJECTIVE The aim of our study was estimation of lover urinary tract function in children with monosymptomatic primary nocturnal enuresis without positive reaction for a long non pharmacological therapy. METHODS 54 children after 9-12 months behavioral therapy and short pharmacological treatment (desmopresin) was undergoing urodynamic investigation (uroflowmetry and cystometry). RESULTS Urodynamic disorders was found in 44/54 of estimated children. In 34 of children it was overactive bladder, in 6 patients we found detrusor-sphincter discoordination. Five children had decreased bladder capacity. Next to non pharmacological treatment we used anticholinergic or Baclofen depending on the results of urodynamic tests. The response to the treatment (non bedwetting at all) we observed in 34 children (in 9 of them after 3 months of therapy, in 16 after 6 months of therapy and in 12 after 12 months of therapy). The rest of children had decreased number of wet night per month. CONCLUSIONS The pharmacological treatment of urodynamic disorders helps to children with monosymptomatic primary nocturnal enuresis to lost this symptom.