Purpose of ReviewEosinophilic granulomatosis with polyangiitis (EGPA) represents a rare clinical entity, which is getting increasing attention and relevance in view of our better understanding and newer insights into its pathogenesis. Concomitantly better recognition and understanding of the immune pathophysiologic role of eosinophils provide a solid ground of their role on systemic inflammatory disorders and defense against infectious triggers, especially parasites. This review will focus on describing the physiopathology of eosinophils, as well as providing an in depth description of the natural history, clinical spectrum, and therapy of EGPA.Recent FindingsSeveral studies have aimed at finding useful biomarkers to monitor disease activity, and reported data have shown that eotaxin 3, IL25, IL33, and some eicosanoids to be promising options. Regarding therapeutic advances, recently published studies have revealed the efficacy of mepolizumab during induction and maintenance of EGPA. Recently published data confirmed earlier studies that the use of azathioprine during the induction phase is of no benefit during long-term follow-up. In addition, data from the REOVAS study, which uses rituximab, is still ongoing and apparently with promising results.SummaryEosinophils are involved in several systemic inflammatory disorders, and recent gathered data provide support for their role in triggering EGPA. Better understanding of its pathophysiology should generate newer insights into the pathogenesis, biomarkers of disease activity, and therapeutic targets.