Introduction: At present, the peak urinary Flow Rate (Qmax) is widely used in evaluating patients with benign prostatic hyperplasia (BPH). Cystoscopy is another method used by many urologists to evaluate BPH cases. To evaluate the correlation between the Qmax and obstructive indices of cystoscopy in patients suffering lower urinary tract symptom due to BPH.Methods: This study was performed on patients with lower urinary tract symptom (LUTS) due to BPH. All included patients were evaluated by uroFlowmetry to determine the Qmax and then cystoscopy was performed to evaluate kissing lateral prostate lobes, median lobe presence, bladder neck elevation, elongation of urethrae and bladder trabeculation. Data were compared and analyzed.Results: 154 patients with the mean age of 65±9 years were evaluated. There was a significant difference between the mean Qmax and severity of kissing lateral prostate lobes, elevation of the bladder neck, and bladder trabeculations (P-value≤0.05). Moreover, Qmax had a significant negative correlation with the severity of those parameters.Conclusion: According to present study, severity of kissing lateral prostate lobes, elevation of the bladder neck, and bladder trabeculations inversely correlate with peak urinary Flow Rate and can be used instead or in combination.