Objective: There are many studies showing that cognitive impairment persisted during the remission period in bipolar disorder type 1(BPD1). The end-product of purine catabolism, uric acid, is a natural antioxidant. The purinergic system has a role in the regulation of mood, sleep, energy, cognitive function, and behavior. Several studies have indicated that malfunctioning of the purinergic system might have an impact on the pathophysiology of BPD1. We aimed to compare differences in cognitive functions and serum urate levels between patients with BPD1and healthy controls (HC), and to evaluate the relationship between serum uric acid levels and cognitive functions in the patient group. Methods: This study included 75 euthymic patients with BPD1 and 75 healthy age- and sex-matched individuals. All participants completed a sociodemographic form, the Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), and Montreal Cognitive Assessment Scale (MoCA), and underwent a neuropsychometric battery; blood serum uric acid levels were also measured. Clinical interviews for Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (SCID-I) and Young Mania Rating Scale (YMRS) scores were obtained for the patients; the HC group was investigated using the SCID non-patient version. Results: All of the neurocognitive domains, patients showed worse performance than healthy controls (p