Purpose: Diabetes mellitus (DM) is a chronic metabolic disorder that often leads to complications. We aimed to correlate two complications of DM, polyneuropathy and hyperactive bladder syndrome, using noninvasive measures, such as screening tests. Methods: We included 80 female and 40 male type 2 diabetic patients in this prospective study. Diabetic polyneuropathy evaluations were conducted using the Douleur Neuropathique 4 Questions (DN4), and overactive bladder (OAB) evaluations were performed using the Overactive Bladder Questionnaire (OAB-V8). The patients were also evaluated for retinopathy and nephropathy. The diabetic male and female patients with or without OAB were chosen and compared for microvascular complications (polyneuropathy, retinopathy, and nephropathy). Results: There were no significant correlations between OAB and retinopathy as well as between OAB and nephropathy among diabetic patients (female patients, P >0.05; male patients, P >0.05). However, the patients with OAB were significantly more likely to develop polyneuropathy (female patients, P < 0.05; male patients, P < 0.05). Conclusions: In diabetic patients, OAB and diabetic peripheral neuropathy are significantly correlated. These correlations were demonstrated using short, understandable, valid, and reliable disease-specific tests without invasive measures. Using these screening tests, both neurologists and urologists can easily diagnose these complications.