OBJECTIVE: To determine whether there is any change in ipsilateral radial artery (RA) diameter following access for transradial coronary angiography and to assess any gender-related association with post-procedural radial artery stenosis (RAS) within 12 hours of the procedure. STUDY DESIGN: An observational study. Place and Duration of the Study: Adult Cardiology, Department of Medicine, Aga Khan University Hospital, Karachi, Pakistan, from January to April 2025. METHODOLOGY: Pre- and post-procedure ultrasound within 12 hours of RA was performed on patients undergoing invasive coronary angiography. Diameter measurement was performed using ultrasound. Patient procedure and demographic data were recorded in pro forma forms. The difference between pre- and post-test scores was calculated and checked for normality, using a paired t-test. RESULTS: This study comprised 50 patients, of whom 44% (n = 22) were female, and 56% (n = 28) were male. The mean age was 59.58 years. Mean post-procedure RA diameter was 2.59 mm compared with 2.55 mm pre-procedure, consistent with an overall vasodilatory response, particularly in female patients, as 64% (n = 16) of those with increased post-procedure RA diameter were female, compared with 36% (n = 9) males in this group. CONCLUSION: Transradial access for coronary angiography is not associated with RAS. There is no association of female gender with RAS in the studied subset of Pakistani patients over 12 hours. KEY WORDS: Coronary angiography, Transradial access, Radial artery diameters, Ultrasound vasodilatory response.