ABSTRACT Purpose: Oxybutynin is a powerful anticholinergic drug already known to impair cognition in the elderly. The impact of this drug on cognitive functioning in the pediatric population is unknown. We report the results of a study designed to assess the effect of oxybutynin on cognitive function in children. Materials and Methods: A total of 25 patients presenting with the primary symptom of daytime enuresis were recruited for this nonrandomized trial. All subjects initially received 4 weeks of behavior modification, followed by an additional 4 weeks of behavior modification either alone or with oxybutynin for continued treatment of enuresis. Neuropsychological testing was performed at baseline (4 weeks) and after additional therapy (8 weeks). Results: Patient demographics included a male-to-female ratio of 11:14 and a mean age of 7.2 ± 1.8 years. A total of 10 patients were assigned to the control group receiving behavior modification, and 15 patients were assigned to the treatment group receiving behavior modification plus oxybutynin. The oxybutynin treated patients had a lower overall performance at baseline pretreatment testing. However, performance in this group improved following treatment with oxybutynin. Conclusions: Oxybutynin, a commonly used pharmacological agent in pediatric urology, was not associated with cognitive impairment following treatment. However, we observed lower baseline cognitive functioning in patients whose parents chose oxybutynin over behavior modification alone. This finding may represent a selection bias. However, it also supports the need for a multidisciplinary approach to the treatment of patients with dysfunctional voiding, as some may have cognitive difficulties that have not previously been explored.