INTRODUCTION: Radial artery is the preferred access for coronary interventions. However, the procedure is sometimes interrupted by a spasm which causes pain, prolongs the procedure, and can force the access crossover. AIM: To observe factors contributing to a symptomatic radial artery spasm. MATERIAL AND METHODS: In this prospective study, we present results of 103 consecutive patients regarding radial artery spasm and angiographic image of the punctured artery. Angiography of the radial artery was performed in 70 (68.0%) patients. Potential risk factors for radial artery spasm were evaluated. RESULTS: The overall incidence of the radial artery spasm was high - 25 (24.3%). Signs of spasm were present in 37.1% of radial artery angiographies before the procedure and 60.1% after, however, it did not always indicate a symptomatic spasm. Risk factors related to radial artery spasm included female sex (OR = 2.94, p = 0.02), failure of the first puncture attempt (OR = 3.12, p = 0.014) and use of non-hydrophilic sheath (OR = 9.56, p = 0.036). Radial artery narrowing at the tip of the sheath was also a risk factor for spasm (p = 0.022). No spasms were observed after hydrophilic sheath application (n = 13). The administration of a radial cocktail was not observed to significantly decrease the spasm odds. CONCLUSIONS: Risk factors for radial artery spasm include female sex and multiple puncture attempts. Hydrophilic sheath coating protects against radial artery spasm. Overall signs of a spasm in the angiography are common and do not imply a symptomatic spasm, which can be predicted by a tight narrowing at the tip of the sheath