For years, conventional wisdom has held that patients with asymptomatic ventricular pre-excitation (asymptomatic WPW or WPW pattern) were at low risk for adverse outcomes. This assumption has been challenged more recently in a number of observational/natural history studies as well as in prospective trials in which patients were more aggressively studied via invasive electrophysiology study (EPS) and more aggressively treated, in some cases, with pre-emptive catheter ablation, despite the lack of symptoms. In sum, the data do not definitively support one approach (early, up-stream EPS and/or ablation) vs. the other (watchful waiting with close monitoring). The most recent pediatric and adult guidelines reflect this ambiguity with a broad spectrum of approaches endorsed.