Objectives: We evaluated with urodynamic studies the bladder function of adolescents and adults who had primary nocturnal enuresis (PNE) since early childhood. Materials and Methods: 36 patients (11 males and 25 females), with PNE complaints were included in the study. We recruited all patients older than 12 (mean age: 17,2 years) who presented to our clinic with persistent enuretic symptoms since early childhood. A detailed history and physical examination were performed on all patients (at the first consultation) to document enuretic and other urinary symptoms and previous treatments. Detailed enuretic diary (to document the number of wet nights a week), uroflowmetry, cystometry, pressure flow study and ultrasonography of the urinary tract were also routinely performed to rule out any anatomical anomalies of the urinary tract as well as to assess the functional bladder capacity and emptying efficiency for every patient. For statistical evaluation, we used repetitive Pillia&#8217;s Trace Test. Results: 14 patients had mild (<3nights/week), 11 patients had moderate (3-6 nights/week) and 11 patients had severe (7nights/week) PNE. 18patients (50%) had various urinary symptoms (frequency, dysuria). 10 patients (6 females and 4 males) (28%) had DOA, which was moderate (4 patients) or severe (3 patients) in 70%. 50% of our patients had daytime urinary symptoms in addition to PNE, and the remaining 50% had monosymptomatic PNE. 3 patients&#8217; (8%) bladder capacity was less than 300ml, and 3 patients (8%) had obstructive findings of the lower urinary tract, depicted by urodynamic studies. Conclusions: In adolescents and adults with PNE, urinary symptoms and underlying bladder dysfunction were found to be significantly high. Assesing all patients with urodynamic studies at the onset of treatment would be useful in deciding about the appropriate treatment protocols.