Current pharmacological treatment modalities for urge incontinence and low compliance bladder are limited by a low clinical efficacy and the significant side effects of the standard drugs available. Previous in vitro studies indicated a possible functional relevance of the intracellular phosphodiesterase (PDE)-1 isoenzyme in the regulation of human detrusor smooth muscle contractility. We therefore investigated the effect of the PDE-1 inhibitor vinpocetine in nonresponders to standard pharmacological therapy. In 11/19 patients (57.9%) clinical symptoms and/or urodynamic parameters were improved. Although these initial data are preliminary, they represent the first evidence that isoenzyme-selective PDE inhibition may be a novel approach to the treatment of lower urinary tract disorders.