 Transurethral resection of the prostate TURP is a standard surgical treatment for benign prostatic hyperplasia BPH. Non-conductive irrigation fluid is used to maintain good visibility of the operating field during resection of the prostate. Absorption of this hypotonic solution into the bloodstream can cause fluid overload and dilutional hyponatremia, resulting in adverse cardiovascular and central nervous system effects, transurethral resection TUR syndrome. BPH is common in elderly men above 60 years old. These aged people commonly have diastolic impairment by normal physiologic change without consistent symptom. This study aimed to evaluate the cardiac function focused mainly diastolic function during TURP with transthoracic echocardiography. Also, we will focus the effets of amount of irrgation fluid on left ventricular diastolic function in patients with pre-existing diastolic dysfunction. 