What is the central question of this study? Are the urinary levels of NO and ATP, and their metabolites, associated with the symptom severity of overactive bladder? What is the main finding and its importance? The urinary ratios of [ATP/NO], [ADP/NO] and a combination of these, [ATP/Cr*ADP/Cr]/[NO/Cr] were correlated with overall OAB symptom severity; with the latter also correlating with the severity of urinary frequency and urgency symptoms individually.