Background: Slow coronary flow (SCF) phenomenon is an angiographic finding which is defined as slow contrast passage through coronary arteries which may predispose patients to serious cardiac complications such as fatal arrhythmias. The work aimed to investigate the correlation of QT interval and p wave dispersions with coronary slow flow. Methods: This case control study was conducted on 60 patients whom undergoing coronary angiography (CAG) in Cardiology Department at Zagazig University Hospitals during the period from October 2019 to March 2020. The study population was divided into two groups: CSF Group: included 30 patients with normal coronary arteries (obstructive lesion