Transradial access is a well established approach for coronary angiography and percutaneous coronary intervention. However a major pitfall is radial artery vasospasm, for which several pharmacological agents are being considered. We have used 100 microgram intra-arterial glycerine trinitrate (GTN) only to counter this problem.A study was done in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh and Apollo Hospital, Hyderabad, India from January 2102 to June 2012. Total 80 patients (40 patient in GTN group and 40 patients in GTN+Diltiazem group) were included for CAG±PCI. Patients were randomized into 2 groups to compare intraarterial GTN and a combination of GTN+Diltiazem. Radial artery spasm and patient comfort were assessed in both groups.Radial artery spasm leading to femoral access was statistically insignificant comparing both groups. None of the patients in GTN group had pain or burning sensation during administration, whereas the cocktail group (GTN+Diltiazem) had some discomfort in the form of pain and burning sensation despite aspirating blood and thorough mixture of blood with GTN and Deltiazem. Radial artery spasm rate was almost similar in both group (2 vs 1 out of 40 in each group respectively). Total procedure time from vascular access to sheath removal was almost similar in both groups (15.41±1.3min vs 14.85±1.6min) and total fluoroscopy time in GTN group was 3.1±1.6min and in GTN with diltiazem group was 2.9±4.6min.Intraarterial GTN alone is a safe and equally effective arterial dilator for transradial coronary angiography compared to combined GTN and diltiazem.