A mycotic aneurysm of the distal radial artery following access for cardiac catheterisation is a rare complication that has not been described in the literature. We present the case of an 84-year-old man who developed bacteraemia and cellulitis over his left first dorsal webspace 2 days after undergoing cardiac catheterisation through the distal radial artery at the anatomic snuffbox. Ultrasound scanning and CT imaging were concerning for a possible pseudoaneurysm at that location. Once we confirmed that the patient had adequate flow through his hand with angiography and an Allens test, we explored his left hand and found a mycotic aneurysm of the distal radial artery with surrounding frank purulence. We resected the aneurysm and ligated the artery. Pathology confirmed that this was a mycotic aneurysm. The patient quickly recovered from his infection after this definitive treatment.