Bipolar plasma kinetic (BP) transurethral resection of prostate (TURP) has been proved to be a safe and effective treatment for benign prostatic enlargement (BPE). However, the role of bipolar TURP on large prostates over 100 g compared with open suprapubic prostatectomy (SP) in elderly patients (>65 years) has not ever been studied before. A retrospective analysis of patients' medical records between 2007 and 2012 was performed. A total of 102 patients who underwent SP (n = 44) or BP-TURP [Gyrus Plasma Kinetic™ (Gyrus ACMI, USA)] (n = 58) for obstructive lower urinary tract symptoms due to BPE were included in this retrospective study. Inclusion criteria were age ≥65 years, prostate volume ≥100 g, International Prostate Symptom Score (IPSS) ≥18, and peak urinary flow rate (PFR) ≤15 ml/s. Exclusion criteria were urethral stricture, known history of neurogenic bladder due to neural disorders, previous prostate and/or urethral surgery, bladder stone, bladder cancer, and known prostate cancer. Operation time, hospitalization, and catheter removal times were noted. Patients were re-evaluated at postoperative 3rd and 12th months. Evaluated parameters were IPSS, quality of life (QoL), simplified International Index of Erectile Function-5 (IIEF-5), PFR, post-voiding residual urinary volume (PVR). Statistical significance was set at 0.05 and all tests were two-tailed. Preoperative IPSS, PVR, IIEF-5, QoL, and prostate volume were not statistically significantly different between two groups except for PFR. Mean follow-up for BP-TURP and SP groups were 15.0 ± 5.8 (R: 11-38), 22.1 ± 11.2 (R: 11-59) months, respectively (p < 0.001). When compared with SP, mean catheter removal time (p < 0.001) and median hospitalization time (p < 0.001) were significantly shorter in BP-TURP group. However, mean operative time was significantly (p < 0.001) longer than SP group and also median resected material weight was significantly lower in the BP-TURP group (p < 0.001). IPSS, QoL, PFR, PVR, and IIEF-5 scores at postoperative 3rd and 12th month were not significantly different between the two groups (p > 0.05). Thirty-three patients had perioperative complications according to the modified Clavien-Dindo system. Thirteen patients (22.4 %) in BP-TURP group and 20 patients (45.4 %) in SP group had complications. In 12th month follow-up visit, four patients presented with urethral stricture, three patients (5.1 %) were in BP-TURP group, and one patient (2.3 %) in SP group (p = 0.455). All strictures were treated with internal urethrotomy. BP-TURP is a safe and highly effective treatment modality for BPE in the elderly patients with prostate glands over 100 g. Clinical efficacy and postoperative 12th month's results were similar to SP. Larger studies with longer follow-up are needed in order to confirm our findings.