Obsessive compulsive and impulsive symptoms are prevalent in patients with Tourette's Syndrome (TS) and well recognized as part of the TS spectrum. However, some complex obsessive compulsive and impulsive behaviors may be mistaken for other symptoms, such as complex tics or psychotic behavior. In addition, the overlap between tics, compulsions, and impulsive actions can make them impossible to discern from each other. Yet, the proper recognition of these symptoms is critical in optimizing treatment outcome in TS patients. This paper will review complex obsessive compulsive and impulsive behaviors that may occur in patients with TS and discuss implications for diagnosis and treatment.