The aim of the study was to investigate safety and efficacy of spasmex (trospium chloride) in patients with idiopathic and neurogenic detrusor overactivity. The study included 66 patients with idiopathic and neurogenic detrusor overactivity. The diagnostic scheme consisted of voiding dairy for 72 hours, laboratory tests, ultrasound investigation with measurement of residual urine volume, urodynamic investigation and neurologic examination. The patients were divided into 4 groups: 15 patients with idiopathic detrusor overactivity (DOA), 16 with neurogenic DOA, 23 with combination of DOA with benign prostatic hyperplasia, 12 with overactive bladder without DOA. Initial trospium chloride dose of 15 mg/day (5 mg 3 times a day) followed by dose titration to obtain clinical efficacy was used under residual urine volume control every week. The maximal dose was 45 mg. After 12 weeks reduction of micturation frequency was registered in all the groups. Administration of small dose trospium chloride (15 mg) resulted in subjective improvement in 63 (94.5%) patients. Only 3 patients persisted with the symptoms in whom the dose was raised to 30 mg and then to 45 mg/day. Thus, spasmex demonstrated high efficacy in patients with bladder overactivity. High efficacy and safety with low cost make spasmex a drug of choice in the majority of patients with overactive bladder symptoms.