INTRODUCTION Benign prostatic hyperplasia (BPH) may ultimately result in acute urinary retention (AUR). This study was performed to assess the impact of transurethral resection of the prostate (TURP) on urodynamic parameters in patients with BPH using pre- and postoperative pressure-flow studies (PFS) and compare those between patients with and without preoperative AUR. PATIENTS AND METHODS 78 patients underwent TURP because of symptoms due to BPH and were evaluated preoperatively and at follow-up after a mean ± SD of 27 ± 11.5 months by the International Prostate Symptom Score and PFS. RESULTS 32% of patients were admitted with AUR. The clinical and principal urodynamic parameters exhibited statistically significant improvement reaching normal values after TURP in most patients. Comparing patients with and without AUR, the bladder compliance significantly increased (p = 0.0013) from the preoperative period to follow-up only in patients with preoperative AUR. The minimal opening pressure decreased significantly more (p = 0.0077) from the preoperative period to follow-up in the non-AUR group. Patients older than 80 years and younger patients showed comparable results. CONCLUSIONS TURP leads to a sustained and age-independent improvement of clinically relevant PFS parameters in patients with BPH. Patients with preoperative AUR had comparable symptomatic, but an impaired urodynamic outcome compared to patients without AUR.