Overactive bladder is a chronic and debilitating condition characterised by urinary urgency with or without urge incontinence, usually in combination with increased urinary frequency and nocturia. Historically, oxybutynin has been the most widely used agent for the treatment of overactive bladder; however, antimuscarinic side effects, in particular dry mouth (xerostomia), can result in poor patient compliance and early cessation of therapy, limiting its clinical usefulness. Tolterodine is better tolerated than other antimuscarinic agents due to its selectivity for the bladder over the salivary gland, and immediate-release tolterodine ['Detrol'; 'Detrusitol'] 2mg twice daily is well established as an effective treatment regimen for overactive bladder. A once-daily extended-release (ER) formulation of tolterodine ['Detrol LA'; 'Detrusitol SR'] has been developed with the intention of improving efficacy, tolerability, and long-term patient compliance and persistence with therapy. Two studies presented at the XVIIth Congress of the European Association of Urology (EAU) [Birmingham, UK; February 2002] demonstrated that tolterodine ER is effective in the treatment of adults with overactive bladder. Other studies presented at the meeting showed that the efficacy of immediate-release tolterodine in such patients can be increased by simplified bladder training, and reported tolterodine's suitability for use in men with bladder outlet obstruction.