The diagnosis of microvascular disease can be challenging for clinicians. It is an important cause of chest pain, especially In women. Making the correct diagnosis is critical in order to instigate the appropriate therapy and avoid unnecessary downstream investigations. The aim of this review by M. Pelletier-Galarneau (Canada and USA) is to provide an update on the use of positron emission tomography (PET) with myocardial blood flow quantification for the diagnosis and management of patients with microvascular disease. It presents a brief overview of the technical aspect of flow quantification with PET and the epidemiology and pathophysiology of microvascular angina, and dsicusses the growing role of PET imaging in the diagnosis and prognostication of patients with suspected microvascular dysfunction. Take-home message: As the non-invasive gold standard for myocardial blood flow quantification, PET will continue to play a central role in the evaluation of patients with suspected microvascular angina.