AbstractBackgroundCoronary artery spasm is an established mechanism of myocardial infarction with non-obstructive coronary arteries (MINOCA). Various mechanisms have been proposed, ranging from vascular smooth muscle hyperreactivity to endothelial dysfunction, to autonomic nervous system dysregulation.Case summaryWe report a case of a 37-year-old woman who presented with recurrent non-ST elevation myocardial infarction (NSTEMI), coinciding with her menstrual periods. Intracoronary acetylcholine provocation testing resulted in coronary spasm in the left anterior descending artery (LAD) that was relieved with nitroglycerine. Initiating calcium channel blockade and suppressing cyclical variation in sex hormones resulted in improvement of her symptoms and cessation of monthly NSTEMI events due to coronary spasm.DiscussionInitiating calcium channel blockade and suppressing cyclical variation in sex hormones resulted in improvement of her symptoms and cessation of monthly NSTEMI events due to coronary spasm. Catamenial coronary artery spasm is a rare, but clinically important, presentation of myocardial infarction with non-obstructive coronary arteries (MINOCA).