Background: During the transradial approach, radial artery spasm is common complication that might make the patient uncomfortable or make it impossible to complete the treatment for patients over 40years old. Objective: It was to compare the conventional spasmolytic drug (verapamil) with a placebo. Patients and Methods: We conducted a randomised, double-blind, prospective study at two-center. After being randomly assigned to receive 2.5mg verapamil after sheath insertion and another 2.5mg before sheath removal at the end of the cardiac procedure (each diluted in 5ml normal saline) or placebo 5ml of normal saline after sheath insertion and before removal, 150 patients (75 in each group) who underwent a transradial cardiac catheterization were subsequently included. Results: The rate of radial occlusion was nearly the same in both groups (10% vs. 15% in verapamil and placebo treated patients, respectively) at the 24-hour follow-up evaluation of the radial artery patency by pulse oximetry and radial arterial duplex. The rate of radial artery blockage was essentially the same in both groups, with insignificant p-value=0.273. There was no statistically significant differences between the two agents in lowering of the radial occlusion rate when verapamil was used (65% had patent arteries with normal flow) or normal saline (60% had patent arteries with normal flow). Conclusion: Verapamil might not be even required as a preventative measure during transradial treatments. Absence of verapamil might not only lower the drug-related problems, but also enable the safe application of transradial technique to patients who are verapamil-incompatible.