Background: dialysis adequacy refers to the delivery of a dose of dialysis considered high enough to promote an optimal long term outcome. Quantification of the dialysis dose is an essential element because the adequacy has a profound effect on patient morbidity and mortality. Aim of the study: assessment the effect of blood and fistula flow rates on dialysis adequacy, phosphate removal and cardiac function in hemodialysis patients. Patients and Methods: this study was conducted on eighty patients with regular hemodialysis (HD) selected from Al-Azhar University Hemodialysis Unite in New Damietta. The studied patients were divided into two main groups according to blood flow rate (BFR) as follows: Group A 40 patients on BFR 250 mL/min and Group B 40 patients on BFR 350 mL/min. Results: there was statistically significant decrease of pre dialysis phosphate in group A in comparison to group B. There was statistically significant increase of KT/V, UUR and PRR in group B in comparison to group A. Arteriovenous fistula (AVF) Qa had negative correlation with TAPSE while it had positive correlation to all echocardiography findings except EF and heart rate (HR), kt/V and URR in group A. AVF Qa had positive correlation to all echocardiography findings except (EF, HR and TAPSE), kt/V, URR and PRP in group B Conclusion: increasing of blood and fistula flow rates are effective in increasing dialysis adequacy and phosphate reduction ration and it is more evident where using high-flux hemodialysis.