Background: Benign prostatic hyperplasia (BPH) is a common urological problem more frequently seen in elderly people causing lower urinary tract symptoms (LUTS). About 28% of patients with BPH have moderate or severe LUTS and a considerable portion of these patients require LUTS treatment, pressure flow studies PFS is the gold standard for diagnosing obstruction, however the test is invasive, unpleasant costly, time consuming and technically difficult with limited availability to the patient. Objective: To evaluate the accuracy of the bladder and prostate sonomorphologic parameters for the diagnosis of bladder outlet obstruction (BOO) in patients with lower urinary tract symptoms (LUTS) with benign prostatic hyperplasia (BPH). Patients and Methods: A prospective clinical trial was carried out during the period from January 2017 to January 2019 at the Urology Departments; Al-Hussein and Sayed Galal, Al-Azhar University Hospitals, and Police Authority Hospital, Cairo, Egypt to 512 patients seeking treatment for LUTS/BPH underwent a series of measurements, including medical history with LUTS assessment using the International Prostate Symptom Score (IPSS), physical examination with digitorectal and focal neurological examinations, routine urinalysis, and serum creatinine and prostate-specific antigen (PSA) measurements. Results: During the study period, 209 patients completed the follow up protocol and included in the study, the mean age of the study population was 64.51 years, the mean total IPSS score was 19.18, the mean duration of symptoms was 6.4 mo., the mean total prostate volume, transitional zone volume, and transitional zone index were 42.5 g, 25.7 g, and 0.6 respectively. The mean bladder parameters studied intravesical prostatic protrusion, bladder wall thickness was 11.3 mm, 4.85 mm, 30.1 g respectively, the mean prostate parameters studied prostate urethral length, prostate urethral angel were 41.8 mm and 34.3˚. Out of 209 patients studied 113 (54.1%) patients were obstructed (BOO group) and 96 (45.9%) were not (non- BOO group). All parameters were comparable between the two groups. Conclusions: Some sonomorphologic parameters of bladder and prostate (IPP, PUA, BWT and Qmax) are useful alternative to PFS for diagnosis of symptomatic BOO/BPH.